Friday, December 12, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
FRIDAY, DECEMBER 12, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0704E
SUNSET: 1612E
BLUSTERY CONDITIONS TODAY ON GREAT BLUE HILL, WITH COLD
TEMPS YET PLENTY OF SUNSHINE….
Today has been beautiful with plenty of all day sunshine.
Unfortunately, it has been cold and blustery. This morning we
dipped down to 18F and just hit the freezing mark by 1pm. Dry
arctic air and gusty WNW winds have kept us reaching for our
mittens, hats and scarfs! Winter is in full force today.
Temperatures have been unseasonably cold today, which tends to
happen behind an arctic front. The air has been dry, with dew
points in the single digits and teens, further adding a chill
to the air. Breezy conditions have added an additional layer of
bitter cold to the equation, with wind chill values starting from
the single digits this morning to the lower 20’s by afternoon.
The wind has had another active day today, with gusty winds out
of the west to west-northwest. So far, the average is around 18mph
for the day so far, with frequent gusts well over 30mph. The peak
gust so far of 41mph occurred just before 12:30pm.
Visibility has been improving as the day has progressed, rising
from around 50 miles this morning to 70 miles by 1pm.
The maximum temperature so far today is 32F degrees, which is
9 degrees below the normal high of 41F. The minimum temperature
since midnight is 18F degrees, which is 8 degrees above the
normal low of 26F.
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Today’s Observations:
7 A.M.
Weather: Clear, few stratocumulus NE-SE-SSW
Temperature: 18F; Dew Point: 9F; Relative Humidity: 67%
Wind: W @ 12G22 kts
Sea-level pressure: 1009.9 mb; 29.82 in. Hg: rising, then more
slowly
Visibility: 50 miles
6-hr Max temp: 21F
6-hr Min temp: 18F
24-hr Precip: 0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 CLR 50 099/18/9/2612G22/982/ FEW SC NE-SE-SSW 8/500
51025 10021 20018
10 A.M.
Weather: Clear, few stratocumulus all quadrants
Temperature: 25F; Dew Point: 9F; Relative Humidity: 49%
Wind: WNW @ 17G32 kts, peak wind WNW 36mph at 9:52 A.M.
Sea-level pressure: 1011.1 mb; 29.86 in. Hg: rising, then more
slowly
Visibility: 60 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 60 111/25/9/2817G32/986/ FEW SC ALQDS PK WND
2931/52/ 8/500 51012
1 P.M.
Weather: Clear, few stratocumulus all quadrants
Temperature: 32F; Dew Point: 15F; Relative Humidity: 49%
Wind: WNW @ 20G36 kts, peak wind WNW 41mph at 12:20 P.M.
Sea-level pressure: 1009.3 mb; 29.80 in. Hg: falling, then
more slowly
Visibility: 70 miles
6-hr Max temp: 32F
6-hr Min temp: 18F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 CLR 70 093/32/15/2920G36/980/ FEW SC ALQDS
PK WND 2836/20/ 8/500 56018 10032 20018
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SUMMARY FOR THURSDAY, DECEMBER 11, 2025
TEMPERATURE (DEGREES F)
MAX…….37 NORMAL…..41
MIN…….21 NORMAL…..26
MEAN……29 NORMAL…..34
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-5
TOTAL DEPARTURE FOR THE MONTH………………………-74 [-6.9 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY…………….36 DEPARTURE……..+5
TOTAL HEATING UNITS FOR THE MONTH……………400 DEPARTURE…….+73
TOTAL HEATING UNITS FOR THE SEASON………….1517 DEPARTURE…….-13
TOTAL HEATING UNITS LAST SEASON TO DATE……..1283 DEPARTURE……+234
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 *=Last of multiple occurrences
F420C (Official)………..51 WNW @ 06:50 P.M.
VECTOR #1 (1-Sec)……….51 WNW @ 06:50 P.M.
VECTOR #2 (1-Sec)……….57 W @ 06:39 P.M.
DAVIS #1……………….52 W @ 04:49 P.M.
DAVIS #2 ………………52 WNW @ 06:39 P.M.
RMY #1 (Instantaneous)…..53 W @ 05:13 P.M.
RMY #2 (Instantaneous)…..60 W @ 04:49 P.M.
MERLIN…………………50 WNW
RICHARDS (C5C) (Inst)……54 W @ 06:44 P.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………40 W @ 04:51 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..35 WNW @ 10:36 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..38 W @ 04:51 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………38 W @ 10:37 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………38 W @ 04:51 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..33 WNW @ 10:36 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..37 W @ 04:51 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………35 WNW @ 10:36 A.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..20.5 W [492 total miles]
VECTOR #1………………19.5
VECTOR #2………………20.6
DAVIS #1……………….20.7 W
DAVIS #2……………….20.7 WNW
RMY #1…………………18.5 W
RMY #2…………………20.0 W
RICHARDS (C5C)………….19.2
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.18
TOTAL PRECIPITATION FOR THE MONTH…………..0.95 DEPARTURE…..-1.02
TOTAL PRECIPITATION FOR THE YEAR (2025)…….45.41 DEPARTURE…..-5.03
SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…..-0.4
TOTAL SNOWFALL FOR THE MONTH………………..0.6 DEPARTURE…..-2.7
TOTAL SNOWFALL FOR THE SEASON (2025-2026)…….0.7 DEPARTURE…..-5.1
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PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 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
12/1 42/27/35/-2/T/0.0/547/98 37 WNW VEC1 37 WNW RMY 38
12/2 36/27/32/-5/0.85/T/000/00 38 N VEC1 38 NNE RMY 38
12/3 37/27/32/-4/0.06/0.6/423/76 28 NW VEC1 29 NNW RMY 30
12/4 38/15/27/-9/T/T/255/46 60 NW VEC1 59 WNW RMY 61
12/5 25/8/17/-19/T/T/510/92 30 NW VEC1 30 NW RMY 30
12/6 39/25/32/-3/T/T/122/22 21 W VEC1 21 W RMY 22
12/7 39/27/33/-2/0.00/0.0/248/45 24 W VEC1 24 W RMY 24
12/8 31/12/22/-13/T/T/…/.. 43 NW VEC1 43 NW RMY 44
12/9 28/9/19/-15/0.00/0.0/…/.. 33 SSW VEC1 33 SSW RMY 33
12/10 46/28/37/+3/0.04/T/…/.. 50 SSW VEC1 50 SSW RMY 51
12/11 37/21/29/-5/0.00/0.0/…/.. 51 WNW VEC1 51 WNW RMY 53
12/12 The low since midnight is 18F, the daily normal low is 26F.
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DECEMBER DAILY RECORDS TO DATE
NONE.
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DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR DECEMBER 12
HIGH 67 IN 1979
LOW -3 IN 1988
PRECIP 3.94 INS. IN 1992
SNOWFALL 20.3 INS. IN 1960
PEAK GUST 75 MPH SSE IN 2008
RECORDS FOR DECEMBER 13
HIGH 60 IN 1984
LOW 0 IN 1893
PRECIP 1.45 INS. IN 1983
SNOWFALL 9.2 INS. IN 2007
PEAK GUST 81e WNW IN 1976
TODAY’S REPORT PREPARED BY: Amanda Joly
