Friday, July 18, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
FRIDAY, JULY 18, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0424E
SUNSET: 1917E
DRY AIR MASS MOVES THROUGH LEAVING MORE SEASONABLE TEMPERATURES
AND LOWER DEW POINTS….
A dry air mass moved over the area late last night and has left
behind partly cloudy skies and much more comfortable temperatures.
Our temperature this morning at 7am was lower than the dew point
at the same time yesterday! It has been a complete change (in a
good way). High pressure has slowly been building today, so all
that has been in the way of weather to report is seasonable
temperatures and fair weather clouds.
The temperature has not yet reached the expected normal for this
time of year, and seems like it may not get there today. Even with
all day sunshine we have managed to stay below 80F. The overnight
low was still above normals but finally got below 70F for the first
time since the early AM hours on Monday.
Wind has remained steady with some gusty conditions at times. Last
night the wind shifted to the northwest which is where it has been
for most of the day. The air has been cooler and drier and has been
a nice welcome from earlier in the week. The average speed for the
day so far is around 14mph. The peak gust so far is 36mph, which
occurred right around 12:30am this morning.
Visibility has been spectacular today, thanks to the lower dew
points. We started at around 60 miles this morning and enjoyed
around 70 miles for the rest of the morning and early afternoon.
The maximum temperature so far today is 79F degrees, which is
3 degrees below the normal high of 82F. The minimum temperature
since midnight is 69F degrees, which is 5 degrees above the normal
low of 64F.
————————————————————–
Today’s Observations:
7 A.M.
Weather: Scattered altocumulus, scattered cirrus, few stratocumulus
all quadrants
Temperature: 74F; Dew Point: 62F; Relative Humidity: 66%
Wind: NW @ 11G18 kts
Sea-level pressure: 1013.3 mb; 29.92 in. Hg: rising, then more
rapidly
Visibility: 60 miles
6-hr Max temp: 74F
6-hr Min temp: 69F
24-hr Precip: 0.00 inches
BHO SA 1155 120 SCT 250 SCT 60 133/74/62/3111G18/992/ FEW SC ALQDS/
8/551 53027 10075 20069
10 A.M.
Weather: Broken altocumulus, broken cirrostratus
Temperature: 73F; Dew Point: 59F; Relative Humidity: 61%
Wind: NNW @ 12G19 kts
Sea-level pressure: 1016.0 mb; 30.00 in. Hg: rising, then more
rapidly
Visibility: 70 miles
3-hr Precip: 0.00 inches
BHO SA 1455 180 BKN 220 BKN 50 SCT 70 160/73/59/3212G19/000/
8/256 53027
1 P.M.
Weather: Scattered altocumulus, scattered cirrostratus, few cumulus
all quadrants
Temperature: 78F Dew Point: 58F; Relative Humidity: 48%
Wind: NW @ 10 kts
Sea-level pressure: 1016.8 mb; 30.03 in. Hg: rising, then more
slowly
Visibility: 70 miles
6-hr Max temp: 79F
6-hr Min temp: 75F
6-hr Precip: 0.00 inches
BHO SA 1755 180 SCT 220 SCT 70 168/78/58/3010/003/ FEW CU ALQDS/
8/256 51008 10079 20075
————————————————————–
SUMMARY FOR WEDNESDAY, JULY 17, 2025
TEMPERATURE (DEGREES F)
MAX…….89 NORMAL…..82
MIN…….73 NORMAL…..64
MEAN……81 NORMAL…..73
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+8
TOTAL DEPARTURE FOR THE MONTH………………………+53 [+3.1 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..0 DEPARTURE………0
TOTAL HEATING UNITS FOR THE MONTH……………..1 DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE SEASON…………….1 DEPARTURE……..-3
TOTAL HEATING UNITS LAST SEASON TO DATE………..0 DEPARTURE……..+1
COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY…………….16 DEPARTURE……..+8
TOTAL COOLING UNITS FOR THE MONTH……………180 DEPARTURE…….+50
TOTAL COOLING UNITS FOR THE SEASON…………..380 DEPARTURE……+111
TOTAL COOLING UNITS LAST SEASON TO DATE………385 DEPARTURE……..-5
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)……….E41 WNW @ 11:57 P.M.
VECTOR #1 (1-Sec)……….41 WNW @ 11:57 P.M.
VECTOR #2 (1-Sec)……….42 WNW @ 11:57 P.M.
DAVIS #1……………….38 W @ 11:57 P.M.
DAVIS #2 ………………41 WNW @ 11:57 P.M.
RMY #1 (Instantaneous)…..42 WNW @ 11:57 P.M.
RMY #2 (Instantaneous)…..42 WNW @ 11:56 P.M.
MERLIN…………………39 W
RICHARDS (C5C) (Inst)…..OTS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………27 WNW @ 11:58 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..27 @ 11:58 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..30 @ 11:58 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………29 W @ 11:57 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………30 W @ 11:58 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..25 WNW @ 11:58 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..29 WNW @ 11:58 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..14.2 SW [340 total miles]
VECTOR #1………………14.1
VECTOR #2………………14.8
DAVIS #1……………….13.8 SW
DAVIS #2……………….14.7 SW
RMY #1…………………13.7 SW
RMY #2…………………14.7 SW
RICHARDS (C5C)…………..OTS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.11
TOTAL PRECIPITATION FOR THE MONTH…………..5.20 DEPARTURE…..+3.30
TOTAL PRECIPITATION FOR THE YEAR (2025)…….28.43 DEPARTURE…..-0.70
————————————————————–
PRELIMINARY CLIMATE SUMMARY FOR JULY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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
7/1 90/68/79/+8/0.14/411/45 38 W VEC1 38 W RMY 41 TSTM
7/2 85/69/77/+6/0.02/247/27 23 WSW VEC1 24 WSW RMY 24
7/3 88/63/76/+4/0.03/748/82 39 SW VEC1 39 SW RMY 40 TSTM
7/4 80/60/70/-2/0.00/875/96 28 NNW VEC1 27 NNW RMY 29
7/5 83/61/72/0/0.00/664/73 23 W VEC1 23 W RMY 24
7/6 92/65/79/+7/0.00/818/90 29 SW VEC1 29 SW RMY 29
7/7 88/69/79/+7/0.01/490/54 28 SSW VEC1 28 SSW RMY 29 TSTM
7/8 94/67/81/+9/0.36/562/62 24 WSW VEC1 24 WSW RMY 27 TSTM
7/9 74/65/70/-3/0.73/172/19 26 SW VEC1 27 SW RMY 28 TSTM
7/10 66/61/64/-9/3.85/000/00 24 ENE VEC1 24 ENE RMY 24 TSTM
7/11 80/62/71/-2/0.00/190/21 18 SSW VEC1 18 SSW RMY 18
7/12 84/65/75/+2/0.00/505/56 20 S VEC1 20 S RMY 19
7/13 85/63/74/+1/0.00/505/56 21 SSW VEC1 21 SSW RMY 21
7/14 81/65/73/0/T/216/24 23 SW VEC1 23 SW RMY 25
7/15 90/71/81/+8/0.06/665/74 24 SSW VEC1 24 SSW RMY 24
7/16 93/71/82/+9/0.00/690/77 24 SSW VEC1 24 SSW RMY 23
7/17 89/73/81/+8/0.00/…/.. 41 WNW VEC1 41 WNW RMY 42
7/18 The low since midnight is 69F, the daily normal low is 64F.
————————————————————–
JULY DAILY RECORDS TO DATE
7/10 RECORD HIGHEST PRECIPITATION OF 3.85 INCHES;
BEATING OLD RECORD OF 1.95 INCHES SET IN 2015
7/16 TIED RECORD HIGH MINIMUM TEMPERATURE OF 71F;
ALSO SET IN 1901, 1958, 1968, 2013, AND 2023
————————————————————–
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR JULY 18
HIGH 96F IN 1991, 1999
LOW 54F IN 1892, 1956, 1971
PRECIP 1.65 INS IN 2000
WIND 43e MPH SW IN 1949
RECORDS FOR JULY 19
HIGH 96F IN 1977, 1991
LOW 50F IN 1890
PRECIP 1.10 INS IN 1951
WIND 63 MPH SSW IN 1982
TODAY’S REPORT PREPARED BY: Amanda Joly
