Friday, May 23, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
FRIDAY, MAY 23, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0415E
SUNSET: 1907E
COASTAL SYSTEM MOVES THROUGH EARLY AM, MOSTLY CLOUDY AND DRY
DURING THE AFTERNOON ….
The impacts of the rare May Nor’easter were certainly felt here
on the summit of Great Blue Hill. We received an impressive storm
total of 3.74″ of rain and had a peak gust of 46mph, which occurred
at 3:24pm. Maybe not surprising is that this large amount of rain
still puts us at a deficit for the season, but we are +4.47″ for
the month. We are currently at 7.09″ of rain for the month of May!
The last of the rain from the storm moved through just before 5:30AM
standard time, and since then we have been under overcast and mostly
cloudy conditions. The sun did come out very briefly in the early
afternoon. There appeared to be some clearing to the southwest and SSW,
but by 1pm we were under overcast conditions again.
Temperatures have remained below normal for another day, but with
the system moving out and some peeks of sun we have thankfully started
to warm and dry out a bit. During the early morning we hit a low of
41F which is just a couple degrees warmer than our record low. By this
afternoon we were hovering in the low 50s which, compared to yesterday
feels much nicer.
The wind was mostly out of the NNW and NW today with a shift to the
WNW by early afternoon. The intensity of the winds were highest during
the overnight hours and have since decreased to around 10mph after the
system had moved through. The average speed for the day so far is around
13mph. The peak gust so far for the day is 45mph, which occurred just
after 1am when the storm was still impacting the area.
Visibility has recovered nicely since yesterday. This morning there
were some low clouds giving us about 60 miles, but once the air dried
a bit more and the clouds lifted we improved to around 70 miles.
The maximum temperature for today is 55F degrees, which is 13 degrees
below the normal high of 68F. The minimum temperature since midnight
is 41F degrees, which is 9 degrees below the normal low of 50F.
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Today’s Observations:
7 A.M.
Weather: Overcast stratus, few lower stratus fractus all quadrants
Temperature: 42F; Dew Point: 42F; Relative Humidity: 100%
Wind: NNW @ 9 kts
Sea-level pressure: 1006.3 mb; 29.72 in. Hg: rising, then more
rapidly
Visibility: 60 miles
6-hr Max temp: 42F
6-hr Min temp: 41F
24-hr Precip: 3.66 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 E8 OVC 60 063/42/42/3309/972/ FEW LWR STFRA ALQDS/
8/7// 53017 6050/ 70366 10042 20041
10 A.M.
Weather: Overcast stratocumulus
Temperature: 46F; Dew Point: 42F; Relative Humidity: 85%
Wind: NW @ 7 kts
Sea-level pressure: 1008.8 mb; 29.79 in. Hg: rising, then more
rapidly
Visibility: 70 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E15 OVC 70 088/46/42/3107/979/ 8/5// 53025
1 P.M.
Weather: Overcast stratocumulus
Temperature: 54F Dew Point: 43F; Relative Humidity: 66%
Wind: WNW @ 7 kts
Sea-level pressure: 1008.7 mb; 29.79 in. Hg: rising, then falling
Visibility: 70 miles
6-hr Max temp: 55F
6-hr Min temp: 42F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E25 OVC 70 087/54/43/2807/979/ 8/5// 58001 10055 20042
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SUMMARY FOR THURSDAY, MAY 22, 2025
TEMPERATURE (DEGREES F)
MAX…….45 NORMAL…..68
MIN…….42 NORMAL…..50
MEAN……44 NORMAL…..59
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………-15
TOTAL DEPARTURE FOR THE MONTH………………………+44 [+1.8 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….21 DEPARTURE…….+14
TOTAL HEATING UNITS FOR THE MONTH……………157 DEPARTURE…….-47
TOTAL HEATING UNITS FOR THE SEASON………….5555 DEPARTURE……-536
TOTAL HEATING UNITS LAST SEASON TO DATE……..5365 DEPARTURE……+190
COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..0 DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH…………….11 DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE SEASON……………14 DEPARTURE……..-2
TOTAL COOLING UNITS LAST SEASON TO DATE………..3 DEPARTURE…….+11
PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all on Main Tower.
E=Estimated
F420C (Official)………..46 NE @ 03:24 P.M.
VECTOR #1 (1-Sec)……….46 NE @ 03:24 P.M.
VECTOR #2 (1-Sec)……….43 NNE @ 05:36 P.M.
DAVIS #1……………….41 NE @ 09:31 P.M.
DAVIS #2 ………………40 ENE @ 03:24 P.M.
RMY #1 (Instantaneous)…..48 NE @ 03:15 P.M.
RMY #2 (Instantaneous)…..44 NNE @ 05:36 P.M.
MERLIN…………………41
RICHARDS (C5C) (Inst)…..OTS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………27 NE @ 03:26 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..27 @ 03:26 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..28 @ 03:26 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………28 NE @ 03:26 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………29 NE @ 03:26 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..26 NE @ 03:26 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..27 NNE @ 03:26 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..17.8 E [426 total miles]
VECTOR #1………………16.2
VECTOR #2………………17.4
DAVIS #1……………….17.7 ENE
DAVIS #2……………….17.4 ENE
RMY #1…………………16.4 ENE
RMY #2…………………17.0 ENE
RICHARDS (C5C)…………..OTS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..3.66 DEPARTURE…..+3.54
TOTAL PRECIPITATION FOR THE MONTH…………..7.09 DEPARTURE…..+4.47
TOTAL PRECIPITATION FOR THE YEAR (2025)…….21.21 DEPARTURE…..-0.19
SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE MONTH………………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……35.8 DEPARTURE…..-33.9
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PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN)/SUN(%)/PEAK GUST/VEC1/RMY GUST
PEAK GUST: F420C (Official)
VEC1: Vector #1 1-second gust
RMY: R.M. Young #1 wind gust recording system (Instantaneous)
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M: Missing data
5/1 69/43/56/+3/0.00/0.0/744/88 28 S VEC1 28 SSW RMY 28
5/2 79/47/63/+9/0.19/0.0/339/40 28 SE VEC1 29 SE RMY 25 TSTM
5/3 84/54/69/+15/0.15/0.0/561/66 43 SSW VEC1 42 SSW RMY 44 TSTM
5/4 77/50/64/+10/0.06/0.0/256/30 33 SW VEC1 34 SW RMY 32
5/5 50/46/48/-7/0.26/0.0/000/00 35 ENE VEC1 35 ENE RMY 36
5/6 61/48/55/0/0.57/0.0/000/00 26 S VEC1 27 ENE RMY 27
5/7 72/54/63/+8/0.01/0.0/310/36 33 SSW VEC1 33 SW RMY 35
5/8 74/51/63/+8/0.04/0.0/474/55 18 ESE VEC1 18 ESE RMY 18
5/9 51/46/49/-7/1.15/0.0/000/00 33 E VEC1 34 ENE RMY 35
5/10 62/45/54/-2/0.29/0.0/121/14 36 NW VEC1 37 NW RMY 41 TSTM
5/11 70/49/60/+4/0.00/0.0/851/98 33 NW VEC1 32 NW RMY 34
5/12 73/46/60/+3/0.00/0.0/853/98 36 SW VEC1 34 SW RMY 36
5/13 70/51/61/+4/0.00/0.0/759/87 26 ESE VEC1 27 ESE RMY 26
5/14 73/48/61/+4/0.00/0.0/586/67 18 SSE VEC1 19 SSE RMY 17
5/15 72/58/65/+8/0.62/0.0/079/09 20 SSE VEC1 20 SSE RMY 19 TSTM
5/16 78/61/70/+12/0.00/0.0/404/46 23 SW VEC1 23 SSW RMY 23
5/17 76/58/67/+9/T/0.0/264/30 30 S VEC1 29 S RMY 30
5/18 68/54/61/+3/T/0.0/512/58 39 W VEC1 39 W RMY 38
5/19 63/46/55/-3/0.00/0.0/371/42 41 NW VEC1 42 NW RMY 44
5/20 55/45/50/-9/T/0.0/000/00 29 NNW VEC1 29 NNW RMY 30
5/21 48/43/46/-13/0.01/0.0/009/01 28 E VEC1 28 E RMY 27
5/22 45/42/44/-15/3.24/0.0/000/00 46 NE VEC1 46 NE RMY 48 TSTM
5/23 The low since midnight is 41F, the daily normal low is 50F.
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MAY DAILY RECORDS TO DATE
5/16 RECORD HIGH MINIMUM TEMPERATURE OF 61F;
PREVIOUS RECORD WAS 60F SET IN 2014
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DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR MAY 23
HIGH 92F IN 1964,1992
LOW 38F IN 1976
PRECIP 1.60 INS IN 1919
PEAK GUST 49e MPH W IN 1945
RECORDS FOR MAY 24
HIGH 92F IN 1964
LOW 35F IN 1956
PRECIP 2.13 INS IN 1951
PEAK GUST 54 MPH NNE IN 2005
TODAY’S REPORT PREPARED BY: Amanda Joly
