March 2026 was generally warm with average precipitation, very little snow, and below average sunshine. The approximated 24-hour mean temperature for the month of 39.4 deg F was 4.9 degrees warmer than the 1891-2020 130-year average for March, and it was 3.6 degrees warmer than the 1991-2020 30-year average. The average maximum temperature of 49.2 deg F was 5.1 degrees warmer than the 30-year normal, and the average minimum temperature of 30.3 deg F was 3.4 degrees warmer than the 30-year normal. After a cold start to the month during the first few days, warmer weather began to arrive, and a total of eighteen days were warmer than average. The highest temperature was 74F on the 10th, which not only surpassed the previous record for the date of 69F set in 1977, but also it was one of the earliest temperatures of 70F or higher on record. The lowest temperature was 8F on the 2nd. March mean water vapor pressure, which is an absolute measure of water vapor in the air, was 6.1 mb, which corresponded to a mean dew point of about 32F. This amount was above the long-term mean water vapor pressure for March of 4.8 mb, which equals a mean dew point of about 27F. The total precipitation was 5.08 inches, which was 0.44 inches less than the 30-year normal. There was frequent precipitation, which was mostly rain, and eighteen days had measurable precipitation. The greatest amount in 24 hours was 1.45 inches on the 16th-17th during the arrival and passage of a very strong cold front on the 17th, which also brought very strong southerly winds. The March total snowfall was just 2.9 inches, which was 12.1 inches less than average. The greatest snowfall in 24 hours was 1.9 inches on the 1st. Ponkapoag Pond was considered thawed on March 21st, which was five days later than average, and Houghton’s Pond followed on the 23rd, which was three days later than average. Since first freezing over on December 6th, Houghton’s Pond was considered ice covered for 107 days, which was the longest interval since the 2013-2014 season. The highest sea-level pressure during March was 30.70 inches on the 2nd, and the lowest sea-level pressure was 29.31 inches during the passage of the very strong cold front and inland storm on the 17th. The mean wind speed was 12.9 mph, which tied as the fourth lowest on record for the month, and the prevailing wind direction was from the south-southwest. The highest wind gust was 81 mph from the south during the strong winds on the 17th. March sunshine was below average with 163.2 hours of bright sunshine, or 46 percent of possible, which was three percent less than the long-term average for the month.

BHO Earliest 70-degree Temperature, deg F (1885-2026):

1) 70 on 21 Feb 2018
2) 71 on 24 Feb 2017
3) 71 on 9 Mar 2000
   75 on 9 Mar 2016
   72 on 9 Mar 2020
6) 74 on 10 Mar 2026
7) 71 on 11 Mar 2021

BHO Lowest March Mean Wind Speed, mph (1885-2026):

1) 12.1 in 1995
2) 12.8 in 2012
   12.8 in 2023
4) 12.9 in 2020
   12.9 in 2024
   12.9 in 2026
7) 13.0 in 2022

Mike Iacono
Chief Scientist
Blue Hill Observatory

Winter 2025-2026 was much colder and snowier than average with less total precipitation and more sunshine than expected. The approximated 24-hour mean temperature for winter of 26.5 deg F was 1.0 degrees colder than the 1891-2020 130-year average for the season, and it was 3.2 degrees colder than the 1991-2020 30-year average. It was the coldest winter at Blue Hill since a mean of 25.3 deg F was observed in winter 2014-2015. The average maximum temperature of 34.5 deg F was 2.8 degrees colder than the 30-year normal, and the average minimum temperature of 18.9 deg F was 2.0 degrees colder than the 30-year normal. Except for a nine-day respite of above average temperatures in mid-January, winter 2025-2026 remained cold throughout with frequent outbreaks of Arctic air. Winter temperatures ranged from a high of 58F ahead of the arrival of an Arctic front on December 19th to a seasonal low of -2F on February 8th. The average water vapor pressure was 3.6 mb, which corresponded to a mean dew point of 21F. This value was lower than the long-term average vapor pressure for winter of 4.0 mb, which corresponds to an average dew point of 23F. The season was much drier than average, and the total liquid equivalent precipitation was 9.32 inches, which was 4.57 inches less than the 30-year normal. The greatest amount in 24 hours was 1.99 inches during the Blizzard of 2026 on February 22nd-23rd. This major ocean storm also brought 24.8 inches of snowfall, which was the fifth largest snowstorm ever observed during February at Blue Hill. The other significant storm of the season was a major snowstorm that brought 25.3 inches of snow on January 25th-26th, which was the third largest January snowfall on record. These storms were the tenth largest and tied for the eleventh largest snowstorms ever measured at Blue Hill, and they were only the third occurrence of two or more snowstorms of twenty inches or more in a single season. The total snowfall for winter was 78.6 inches, which was 29.2 inches more than normal, and it was the eleventh highest winter snowfall on record. The lowest sea-level pressure during winter was 29.30 inches during the blizzard on February 23rd, and the highest sea-level pressure was 30.66 inches on January 25th. The mean wind speed was 12.7 mph, which tied as the third lowest on record for winter, and the prevailing wind direction was from the west-northwest. The highest wind gust during winter was 79 mph from the south ahead of a strong cold front on December 19th, and another notable wind gust was 68 mph from the northeast during the blizzard on February 23rd. Winter sunshine was above average with 442.0 total hours of bright sunshine, or 52 percent of possible, which was four percent more than the long-term average for the season.

BHO Highest Winter (Dec-Feb) Snowfall, inches (1885-2026):

1) 128.8 in 2014-2015
2) 117.4 in 1947-1948
3) 91.2 in 1995-1996
4) 89.6 in 2010-2011
5) 89.0 in 1922-1923
6) 86.4 in 2004-2005
7) 85.8 in 2002-2003
8) 82.7 in 1903-1904
9) 81.9 in 1993-1994
10) 81.6 in 2013-2014
11) 78.6 in 2025-2026

BHO Greatest Snowstorms, inches (1885-2026):

1) 38.7 on 24-28 Feb 1969
2) 30.8 on 26-28 Jan 2015
3) 30.3 on 3-5 Mar 1960
4) 30.1 on 6-7 Feb 1978
5) 30.0 on 31 Mar – 1 Apr 1997
6) 29.8 on 6-8 Mar 2013
7) 28.1 on 7-10 Feb 2015
8) 27.6 on 28-29 Jan 2022
9) 26.6 on 8-9 Feb 2013
10) 25.3 on 25-27 Jan 2026
11) 24.8 on 17-18 Feb 2003
   24.8 on 22-23 Feb 2026

BHO Lowest Winter (Dec-Feb) Mean Wind Speed, mph (1885-86 to 2025-26):

1) 11.6 in 2023-2024
2) 12.2 in 2020-2021
3) 12.7 in 2022-2023
   12.7 in 2025-2026
5) 12.8 in 2019-2020
   12.8 in 2021-2022

Mike Iacono
Chief Scientist
Blue Hill Observatory

True-color visible satellite imagery of the Blizzard of 2026 off the coast of New England near mid-day of 23 February 2026. NOAA imagery courtesy of the College of DuPage (weather.cod.edu).

Blue Hill Observatory February 2026 Summary: 

February 2026 was generally cold with much more snowfall than normal and average sunshine. The approximated 24-hour mean temperature for the month of 26.1 deg F was 0.5 degrees colder than the 1891-2020 130-year average for February, and it was 3.1 degrees colder than the 1991-2020 30-year average. The average maximum temperature of 34.7 deg F was 2.3 degrees colder than the 30-year normal, and the average minimum temperature of 18.3 deg F was 1.2 degrees colder than the 30-year normal. After a cold start to the month during the first ten days, it remained close to average through the end of the month. The highest temperature was 51F on the 28th, and the lowest temperature was -2F on the 8th. February mean water vapor pressure, which is an absolute measure of water vapor in the air, was 3.4 mb, which corresponded to a mean dew point of about 20F. This amount was slightly below the long-term mean water vapor pressure for February of 3.7 mb, which equals a mean dew point of about 22F. The total precipitation was 2.97 inches, which was 1.03 inches less than the 30-year normal. There were frequent light to moderate snowfalls during the month, until the arrival of the very impactful Blizzard of 2026 on the 22nd-23rd. This storm brought 1.99 inches of liquid equivalent precipitation, which was the greatest in 24-hours for the month, and 24.8 inches of snowfall. Blizzard conditions with strong winds occurred for several hours at the Observatory.  This storm was the fifth largest snowstorm ever observed in February at Blue Hill, and it tied as the eleventh largest snowfall for any month of the year. Parts of southeastern New England received all-time record amounts of snow of 30-38 inches. Snowfall rates reached 2-3 inches per hour at the Observatory and exceeded this rate at other locations. The February total snowfall was 35.9 inches, which was 17.7 inches more than average. Snow depth on the ground was 15 inches or higher all month, and the snow depth reached a season high of 28 inches on the morning of the 24th. The average 7 AM snow depth for February was 18.5 inches, which was the sixth highest on record for the month. The highest sea-level pressure during February was 30.22 inches on the 22nd, and the lowest sea-level pressure was 29.30 inches during the passage of the very intense ocean storm on the 23rd. The mean wind speed was 11.8 mph, which was the second lowest on record for the month, and the prevailing wind direction was from the northwest. The highest wind gust was 68 mph from the northeast during the blizzard on the 23rd. February sunshine was near average with 146.8 hours of bright sunshine, or 51 percent of possible, which was one percent more than the long-term average for the month.

BHO Greatest Snowstorms, inches (1885-2026):

1) 38.7 on 24-28 Feb 1969
2) 30.8 on 26-28 Jan 2015
3) 30.3 on 3-5 Mar 1960
4) 30.1 on 6-7 Feb 1978
5) 30.0 on 31 Mar – 1 Apr 1997
6) 29.8 on 6-8 Mar 2013
7) 28.1 on 7-10 Feb 2015
8) 27.6 on 28-29 Jan 2022
9) 26.6 on 8-9 Feb 2013
10) 25.3 on 25-27 Jan 2026
11) 24.8 on 17-18 Feb 2003
   24.8 on 22-23 Feb 2026

BHO Greatest Calendar Day Snowfall, inches (1885-2026):

1) 27.4 on 24 Feb 1969
2) 25.2 on 27 Jan 2015
3) 24.6 on 23 Feb 2026
4) 23.0 on 13 Mar 2018
5) 20.3 on 12 Dec 1960
6) 20.0 on 17 Feb 2003
7) 19.0 on 20 Jan 1978
8) 18.6 on 16 Feb 1958

BHO Greatest February Monthly Snowfall, inches (1885-2026):

1) 83.6 in 2015
2) 65.4 in 1969
3) 51.3 in 2003
4) 45.2 in 1967
5) 40.4 in 1920
6) 39.7 in 2013
7) 39.0 in 2021
8) 37.0 in 1893
9) 36.0 in 1899
10) 35.9 in 2026

BHO Greatest February Monthly Mean Snow Depth, inches (1895-2026):

1) 34.0 in 2015
2) 27.1 in 1920
3) 25.5 in 1948
4) 20.2 in 2011
5) 20.0 in 1978
6) 18.5 in 2026
7) 17.2 in 1961
8) 17.1 in 1904
9) 15.6 in 1969
10) 15.5 in 1926

BHO Greatest February Snowstorms, inches (1886-2026):

1) 38.7 on 24-28 Feb 1969
2) 30.1 on 6-7 Feb 1978
3) 28.1 on 7-10 Feb 2015
4) 26.6 on 8-9 Feb 2013
5) 24.8 on 22-23 Feb 2026
6) 24.7 on 17-18 Feb 2003
7) 22.2 on 16-17 Feb 1958
8) 21.6 on 14-15 Feb 2015

BHO Greatest February Calendar Day Snowfall, inches (1885-2026):

1) 27.4 on 24 Feb 1969
2) 24.6 on 23 Feb 2026
3) 20.0 on 17 Feb 2003
4) 18.6 on 16 Feb 1958
5) 17.1 on 7 Feb 1978
6) 16.5 on 2 Feb 2015
7) 16.9 on 9 Feb 2017
8) 16.1 on 8 Feb 2013

BHO Lowest February Mean Wind Speed, mph (1885-2026):

1) 11.7 in 2021
2) 11.8 in 2026
3) 12.0 in 2020
12.0 in 2024
5) 12.6 in 2014
12.6 in 2023
7) 12.7 in 2005
12.7 in 2012

Mike Iacono
Chief Scientist
Blue Hill Observatory

January 2026 was generally cold with much more snowfall and more sunshine than average. The approximated 24-hour mean temperature for the month of 24.6 deg F was 1.3 degrees colder than the 1891-2020 130-year average for January, and it was 2.6 degrees colder than the 1991-2020 30-year average. The average maximum temperature of 32.7 deg F was 2.0 degrees colder than the 30-year normal, and the average minimum temperature of 17.4 deg F was 0.9 degrees colder than the 30-year normal. After a cool start to the month, it remained warm for nearly two weeks before Arctic air moved in on the 20th and remained through the end of the month. The highest temperature for the month was 51F on the 15th, and the lowest temperature was -1F on the 31st. January mean water vapor pressure, which is an absolute measure of water vapor in the air, was 3.5 mb, which corresponded to a mean dew point of about 20F. This amount was slightly below the long-term mean water vapor pressure for January of 3.8 mb, which equals a mean dew point of about 22F. The total precipitation was 3.62 inches, which was 0.88 inches less than the 30-year normal. Most of this liquid equivalent precipitation fell in frozen form, and the greatest amount in 24-hours was 1.88 inches during a major snowstorm on the 25th-26th, which was a highly impactful snow and ice storm over a large area across the southern and eastern United States. This storm brought a total of 25.3 inches of snow to the Observatory, and the greatest amount in 24 hours was 22.2 inches on the 25th-26th. Snowfall rates reached one to two inches per hour during the evening of the 25th. This storm was the third largest January snowstorm on record at Blue Hill, and it was the tenth largest snowstorm for any month of the year. The January total snowfall was 35.9 inches, which was 17.3 inches more than average. The highest sea-level pressure during January was 30.66 inches on the early morning of the 25th, and the lowest sea-level pressure was 29.31 inches during a period of warm air and strong southwest winds on the 15th. The mean wind speed was 12.5 mph, which was the fifth lowest on record for the month, and the prevailing wind direction was from the west-northwest. The highest wind gust was 53 mph from the east during the storm on the 25th. January sunshine was above average with 145.2 hours of bright sunshine, or 51 percent of possible, which was five percent more than the long-term average for the month.

BHO Greatest Snowstorms, inches (1885-2026):

1) 38.7 on 24-28 Feb 1969
2) 30.8 on 26-28 Jan 2015
3) 30.3 on 3-5 Mar 1960
4) 30.1 on 6-7 Feb 1978
5) 30.0 on 31 Mar – 1 Apr 1997
6) 29.8 on 6-8 Mar 2013
7) 28.1 on 7-10 Feb 2015
8) 27.6 on 28-29 Jan 2022
9) 26.6 on 8-9 Feb 2013
10) 25.3 on 25-27 Jan 2026

BHO Greatest January Snowstorms, inches (1886-2026):

1) 30.8 on 26-28 Jan 2015
2) 27.5 on 28-29 Jan 2022
3) 25.3 on 25-27 Jan 2026
4) 20.5 on 22-23 Jan, 2005
5) 19.0 on 20 Jan, 1978
6) 18.2 on 7-8 Jan 1996
7) 17.6 on 23-24 Jan, 1966
8) 16.7 on 22-24 Jan, 1935
9) 16.5 on 4 Jan, 2018
10) 16.3 on 2-4 Jan, 1996

BHO Lowest January Mean Wind Speed, mph (1886-2026):

1) 11.4 in 2023
2) 11.7 in 2021
11.7 in 2024
4) 12.2 in July 2001
5) 12.5 in 2026

Mike Iacono
Chief Scientist
Blue Hill Observatory

The year 2025 was warmer than average, but it was the coolest year since 2019. The approximated 24-hour mean temperature of 49.9F was 2.1F warmer than the 130-year (1891-2020) long-term mean and 0.4F above the 30-year (1991-2020) average. Ten months during the year were warmer than the long-term mean and two, January and December, were colder than average. The annual average maximum temperature of 59.1F was 0.8F warmer than the 30-year normal, and the annual average minimum temperature of 41.6F was 0.5F warmer than the 30-year normal.

The year started cooler than average, turned warmer during spring and summer with April through July all being among the ten warmest on record, then cooler weather returned later in the year. January was generally cooler than average, and the coldest temperature for the year was 2F on January 22nd. Cold weather continued into much of February until the last week of the month when a high of 55F occurred on February 25th. March turned warmer with 23 days warmer than normal. April had 13 days with high temperatures of 65F or more, including the highest of 82F on April 19th, and the month was the seventh warmest on record. May generally continued the warmth as the eighth warmest on record with the exception of cold weather during a strong nor’easter on May 22nd-23rd, which brought a high temperature of only 45F and a low of 42F on May 22nd. Spring (March-May) 2025 tied as the fourth warmest on record at the Observatory. June was the eighth warmest on record and included seven days that reached or exceeded ninety degrees, which was the largest number of ninety-degree days ever observed in June at Blue Hill. A four-day heat wave occurred on June 22nd-25th, which was one of only three four-day heat waves ever recorded in June at Blue Hill. The highest temperature for the year was 99F on June 24th, which matched the highest temperature ever measured at Blue Hill during June and surpassed the previous record for the date of 91F set in 1914, 1976, and 2013. The second highest daily minimum temperature ever observed in June of 76F was recorded on June 24th and 25th. July was the tenth warmest on record and added eight more ninety-degree days to the annual total of 18, which was eleven more than the long-term average number. Somewhat cooler weather began to return in August, except for a relatively warm period during the second week of the month. September and October were slightly warmer than average with a three-day period of 80F or higher as late as October 4th-6th. Cooler weather returned in November, though the first freeze of the season (temperature of 32F or lower) did not occur until November 7th, which tied as the eighth latest date on record. After seven straight warm Decembers, December 2025 was colder than average and the coldest since 2017, though there were only a few brief periods of Arctic air during the month and no daily records were established. 

Ponkapoag Pond and Houghton’s Pond were first considered frozen for the 2024-2025 winter season during the first half of December 2024, and due to the cool start to 2025, the ponds were considered thawed for that season on March 11th (Ponkapoag) and March 15th (Houghton’s). The freeze interval during that season of 97 days (Ponkapoag) and 89 days (Houghton’s) was slightly shorter than the long-term average. At the start of the 2025-2026 winter season, both ponds were considered first frozen on December 6th, which was a few days earlier than the long-term average date.

The annual rainfall of 47.19 inches was 1.73 inches less than the 130-year average and 6.67 inches less than the 30-year normal. The year started off dry with only 2.35 inches from a handful of precipitation events and no significant storms in January. February added slightly to the deficit, with 1.95 inches of liquid equivalent, more than half of the month’s precipitation, falling as a combination of rain and snow on the 15th-16th. Essentially all of the March precipitation fell as rain, with only a few traces of snowfall, and the largest storm in March brought 2.17 inches of rain on the 16th-17th. Despite 15 days with measurable precipitation, April contributed more than an inch to the annual rainfall deficit. Above normal precipitation returned in May, which brought 7.62 inches of rain, and the month was the eighth wettest May on record. The largest event was a major, late-season nor’easter, which brought 3.74 inches of rain and cold temperatures on May 22nd-23rd. After a dry June, July was very wet, though most of the monthly rain, 4.94 inches, fell during three days with thunderstorms on July 8th-10th, including 2.46 inches over a two-hour period on the morning of July 10th. The greatest rainfall amount in 24 hours during 2025 was 3.85 inches on July 10th. August was relatively dry with only five days with measurable precipitation. September rainfall was near average, with the largest event bringing 2.02 inches on Sep 6th-7th. October featured two significant storms including a coastal storm that brought 3.54 inches of rain on the 12th-14th. The second was a strong inland storm that brought a tropical feed of moisture, strong winds, and 0.96 inches of rainfall on the 29th-31st while a weakening Hurricane Melissa passed far out at sea. Both November and December brought about half of the expected precipitation for those months, though there were frequent moderate events during December. More than twenty inches of the annual rainfall fell during only seven events on sixteen days during the year. There were 22 thunderstorm days during 2025, which matched the average number.

Snowfall was sparse during 2025 with an annual total of just 30.1 inches, which was far less than the recent 30-year normal of nearly 70 inches. The largest snowfall event all year was 5.7 inches on January 18th-19th. Other notable snow events brought 4.1 inches on February 8th-9th, 4.9 inches on February 15th-16th, and 3.6 inches on December 26th-27th. There was just one inch of snow on the ground on Christmas Day morning, which qualified the day as a “White Christmas” at Blue Hill. The long-term chance of a snow depth of one-inch or more on December 25th on the summit of Great Blue Hill is 44 percent.

The mean station pressure during 2025 at the elevation of the mercury barometer at the Observatory was 29.31 inches, which was 0.02 inches above the long-term annual mean of 29.29 inches. The maximum sea-level pressure during the year was 30.65 inches on February 2nd, and the lowest sea-level pressure during 2025 was 28.93 inches just two weeks later during a rain and snow storm on February 16th.

One of the more unusual metrics recorded at the Observatory is the date of the first ripe blueberry on the summit of Great Blue Hill. In 2025 this was observed to occur on June 23rd, which a couple of days later than the long-term average date. In general, this date is trending earlier due to the warming climate.

Water vapor pressure, which is derived from the dew point and is an absolute measure of the amount of moisture in the air in terms of the pressure that water vapor contributes to the total surface pressure, averaged 10.6 mb (0.313 inches) during 2025, which corresponded to a mean dew point of 46 deg F. The annual vapor pressure continued a trend of higher water vapor pressures in recent decades, which is consistent with the increasing trend in temperature. Another way to interpret this value is to state that water vapor on average comprised a little over one percent of the total annual mean station pressure during the year.

The annual mean wind speed of 12.0 mph, while higher than the last two years, tied as the fifth lowest on record for any year. This average continued the several decades long trend of decreasing mean wind speeds on Blue Hill. One month during the year, September, tied the record for the lowest average wind speed for that month, 9.4 mph, previously set in 2024. The prevailing wind direction for 2025 was west-northwest. The peak gust for the year was 79 mph from the south prior to the passage of an Arctic front on December 19th. Other notable wind gusts during the year included 65 mph from the west-northwest on January 28th, 70 mph from the west-northwest on February 17th, and 69 mph from the south on March 6th.

Bright sunshine for the year was 57 percent of possible, which was five percent more than the long-term average. The least sunny month as a percent of possible was May with only 175.1 hours or 40 percent of the possible bright sunshine. The sunniest month during 2025 (relative to the possible sunshine) was August, which had 305.1 hours or 74 percent of the possible sunshine. The August sunshine was enough to make that month the sunniest August on record. For the year, 2025 was the fourteenth sunniest year on record.

BHO Lowest Annual Mean Wind Speed, mph (1885-2025):

1) 10.8 in 2023
2) 11.2 in 2024
3) 11.5 in 2021
4) 11.8 in 2012
5) 12.0 in 2020
   12.0 in 2022
   12.0 in 2025
8) 12.1 in 2018
   12.1 in 2019

Mike Iacono
Chief Scientist
Blue Hill Observatory

December 2025 was colder and drier than normal with less snowfall and much more sunshine than average. The approximated 24-hour mean temperature for the month of 28.9 deg F was 1.2 degrees colder than the 1891-2020 130-year average for December, and it was 3.9 degrees colder than the 1991-2020 30-year average. The month was the coldest December since 2017, and it tied as the fourth coldest since 1990. The average maximum temperature of 36.0 deg F was 4.2 degrees colder than the 30-year normal. The average minimum temperature of 20.9 deg F was 4.0 degrees colder than the 30-year normal, and this measure was the coldest since 2000. The chilly weather continued throughout the month, though there were no daily temperature records, and there were only seven days that averaged warmer than normal. The highest temperature for the month was 58F on the 19th, and the lowest temperature was 8F on the 5th and 26th. December mean water vapor pressure, which is an absolute measure of water vapor in the air, was 3.8 mb, which corresponded to a mean dew point of about 22F. This amount was below the long-term mean water vapor pressure for December of 4.5 mb, which equals a mean dew point of about 26F. The total precipitation was 2.73 inches, which was 2.66 inches less than the 30-year normal. There were no significant storms during the month, though there were several strong frontal passages and smaller rain and snow events. The greatest liquid equivalent precipitation in 24 hours was 0.91 inches on the 2nd-3rd, which was mostly rain that ended as a small snowfall on the 3rd. The total snowfall during December was 6.8 inches, which was 5.8 inches less than normal. There were no thunderstorm day during the month. The lowest sea-level pressure was 29.19 inches during the passage of an Arctic front following a period of rainfall on the 29th, and the highest sea-level pressure was 30.41 inches on the 22nd. It was a relatively windy month, and the mean wind speed was 13.7 mph with a prevailing wind direction from the west. The highest wind gust was 79 mph from the south ahead of another strong cold front on the 19th. Wind gusts exceeded 50 mph on eight days. December sunshine was much above average with 150.0 hours of bright sunshine, or 55 percent of possible, which was nine percent more than the long-term average for the month.

Mike Iacono
Chief Scientist
Blue Hill Observatory

Fall 2025 temperature was above average, precipitation was near average, and there was more sunshine than expected. The approximated 24-hour mean temperature for fall of 53.0 deg F was 1.9 degrees warmer than the 1891-2020 130-year average for the season, and it was 0.5 degrees warmer than the 1991-2020 30-year average. The average maximum temperature of 61.7 deg F was 0.5 degrees warmer than the 30-year normal, and the average minimum temperature of 45.6 deg F was 1.1 degrees warmer than the 30-year normal. Fall 2025 began warmer than average, then it turned cooler than normal from late October through November. Fall temperature ranged from a high of 84F on September 6th to a seasonal low of 27F on November 19th,  20th, and 29th. The average water vapor pressure was 11.3 mb, which corresponded to a mean dew point of 52F. This value was higher than the long-term average vapor pressure for fall of 10.6 mb, which corresponds to an average dew point of 51F. The season was slightly drier than average, and the total precipitation was 13.13 inches, which was 0.73 inches less than the 30-year normal. Half of the fall rainfall fell during the wettest month, October, while November was much drier than average. The greatest amount in 24 hours was 2.69 inches on October 12th-13th, which was about twenty percent of the seasonal rainfall. There were four thunderstorm days during fall, which was one more than average for the season. The first and only measurable frozen precipitation of the season was observed as 0.1 inches of sleet on November 15th, and this amount was below the seasonal average snowfall of 2.5 inches. The lowest sea-level pressure during fall was 29.09 inches during the passage of an inland storm across southern New England on November 16th, and the highest sea-level pressure during fall was 30.55 inches on October 10th. The mean wind speed was 11.3 mph, which was the third lowest on record for fall, and the prevailing wind direction was from the west-northwest. The highest wind gust was 60 mph from the west as a rain storm departed the area early on October 31st. Fall sunshine was above average with 582.3 total hours of bright sunshine, or 60 percent of possible, which was six percent more than the long-term average for the season.

BHO Lowest Fall (Sep-Nov) Mean Wind Speed, mph (1885-2025):

1) 10.4 in 2023
2) 11.1 in 2024
3) 11.3 in 2025
4) 11.4 in 2021
5) 11.6 in 2016
6) 11.7 in 2022

Mike Iacono
Chief Scientist
Blue Hill Observatory

November 2025 was cooler than normal with less precipitation and more sunshine than average. The approximated 24-hour mean temperature for the month of 41.2 deg F was 0.5 degrees warmer than the 1891-2020 130-year average for November, and it was 0.9 degrees cooler than the 1991-2020 30-year average. The average maximum temperature of 48.7 deg F was 1.4 degrees cooler than the 30-year normal, and the average minimum temperature of 33.8 deg F was equal to the 30-year normal. The highest temperature for the month was 61F on the 9th, and the lowest temperature was 27F on the 19th, 20th, and 29th. The first freeze of the season occurred on the 7th, which tied as the eighth latest on record. November mean water vapor pressure, which is an absolute measure of water vapor in the air, was 6.5 mb, which corresponded to a mean dew point of about 34F. This amount was below the long-term mean water vapor pressure for November of 7.0 mb, which equals a mean dew point of about 35F. The total precipitation was 2.15 inches, which was 2.16 inches less than the 30-year normal. There were no significant storms during the month, and the greatest rainfall in 24 hours was 0.56 inches on the 15th-16th. The first measurable frozen precipitation of the season was observed as 0.1 inches of sleet during the evening of the 15th. There were no thunderstorm day during the month. The lowest sea-level pressure was 29.09 inches during the storm on the 16th, and the highest sea-level pressure was 30.52 inches on the 29th. The mean wind speed was 12.6 mph, and the prevailing wind direction was from the west-northwest. The highest wind gust was 52 mph from the northwest on the 4th. November sunshine was above average with 148.7 hours of bright sunshine, or 52 percent of possible, which was four percent more than the long-term average for the month.

BHO Latest First Freeze, (1885-2025):

1) 15 Nov 1938
2) 12 Nov 1943
   12 Nov 1977
4) 11 Nov 1994
5) 10 Nov 1956
6) 9 Nov, 2017
   9 Nov 2022
8) 7 Nov 1971
   7 Nov 2025

Mike Iacono
Chief Scientist
Blue Hill Observatory

October 2025 was warmer than normal with more precipitation and more sunshine than average. The approximated 24-hour mean temperature for the month of 53.6 deg F was 2.3 degrees warmer than the 1891-2020 130-year average for October, and it was 1.4 degrees warmer than the 1991-2020 30-year average. The average maximum temperature of 62.2 deg F was 1.2 degrees warmer than the 30-year normal, and the average minimum temperature of 46.2 deg F was 2.2 degrees warmer than the 30-year normal. The warmest period occurred during the first week of the month, which included three consecutive days that exceeded 80F. The highest temperature for the month was 84F on the 5th, and the lowest temperature was 34F on the 27th. October mean water vapor pressure, which is an absolute measure of water vapor in the air, was 10.9 mb, which corresponded to a mean dew point of about 47F. This amount was above the long-term mean water vapor pressure for October of 10.1 mb, which equals a mean dew point of about 45F. The total precipitation was 6.49 inches, which was 1.00 inches more than the 30-year normal. There were two significant storms during the month including a coastal storm that brought 3.54 inches of rain on the 12th-14th and a peak wind gust to 51 mph from the east-northeast on the 13th. The greatest rainfall in 24 hours was 2.69 inches on the 12th-13th. The second was a strong inland storm that brought a tropical feed of moisture, strong winds, and 0.96 inches of rainfall on the 29th-31st while a weakening Hurricane Melissa passed far out at sea. There was one thunderstorm day during the month, which was average, and the total for the year through October increased to 22, which was also average. The lowest sea-level pressure was 29.11 inches on the 31st, and the highest sea-level pressure was 30.55 inches on the 10th. The mean wind speed was 11.9 mph, and the prevailing wind direction was from the north-northwest. The highest wind gust was 60 mph from the west during the departure of the strong storm on the 31st. October sunshine was above average with 197.1 hours of bright sunshine, or 60 percent of possible, which was five percent more than the long-term average for the month.

Mike Iacono
Chief Scientist
Blue Hill Observatory