Tuesday, December 16, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
TUESDAY, DECEMBER 16, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0707E
SUNSET: 1613E
MORNING CLOUDS GIVE WAY TO SUNSHINE AND MILDER TEMPERATURES….
We started the day with a mid level deck of clouds associated with
a dry warm front that passed through the region early this morning.
The clouds moved out by mid morning with abundant sunshine taking
over thereafter. With much lighter wind and considerably milder
temperatures compared to yesterday, it has turned into a very
decent day out there for mid December standards.
While temperatures are milder than yesterday, they still remain
below normal overall. Readings have reached the mid 30s by early
this afternoon, which is more than 10F degrees warmer than
yesterday. Dew point values have been slowly coming up as well,
rising through the mid to upper teens over the course of the day.
A sign that the arctic air mass is moving out.
The wind has been on the light side today, starting out of the
west then became variable. The average speed for the day so far
is around 8mph, but the trend since early this morning has been
for decreasing speeds. The peak gust for the day so far is 23mph,
which occurred just before 1am this morning.
Visibility has been somewhat limited today due to haziness. The
view has generally been holding around 50-60 miles all day.
The maximum temperature so far today is 36F degrees, which is
4 degrees below the normal high of 40F. The minimum temperature
since midnight is 19F degrees, which is 6 degrees below the
normal low of 25F.
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Today’s Observations:
7 A.M.
Weather: Overcast altocumulus, few breaks in overcast distant NE-SSE,
few stratocumulus offshore distant NE-S
Temperature: 21F; Dew Point: 13F; Relative Humidity: 69%
Wind: W @ 6 kts, wind light
Sea-level pressure: 1022.8 mb; 30.20 in. Hg: rising, then more rapidly
Visibility: 50 miles
6-hr Max temp: 22F
6-hr Min temp: 19F
24-hr Precip: 0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 1 inch
BHO SA 1155 E70 OVC 50 228/21/13/2606/020/ FEW BINOVC DSNT NE-SSE
FEW SC OFFSHR DSNT NE-S WND LGT/ 8/55/ 4/001 53019 10022 20019
10 A.M.
Weather: Clear, few stratocumulus distant NE-E, few altocumulus
distant ESE-SSW
Temperature: 29F; Dew Point: 15F; Relative Humidity: 55%
Wind: S @ 3 kts, wind light
Sea-level pressure: 1022.8 mb; 30.20 in. Hg: rising, then falling
Visibility: 50 miles, hazy
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 50 228/29/15/1903/020/ FEW SC DSNT NE-E
FEW AC DSNT ESE-SSW HAZY WND LGT/ 8/550 50000
1 P.M.
Weather: Clear, few stratocumulus distant ENE-S, few cirrus
distant W-NNW
Temperature: 35F; Dew Point: 18F; Relative Humidity: 49%
Wind: SSW @ 6 kts, wind light
Sea-level pressure: 1021.2 mb; 30.16 in. Hg: falling, then more rapidly
Visibility: 60 miles
6-hr Max temp: 36F
6-hr Min temp: 21F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 1 inch
BHO SA 1755 CLR 60 212/35/18/2106/016/ FEW SC DSNT ENE-S
FEW CI DSNT W-NNW WND LGT/ 8/501 4/001 58016 10036 20021
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SUMMARY FOR MONDAY, DECEMBER 15, 2025
TEMPERATURE (DEGREES F)
MAX…….23 NORMAL…..40
MIN…….10 NORMAL…..25
MEAN……17 NORMAL…..33
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………-16
TOTAL DEPARTURE FOR THE MONTH……………………..-112 [-7.7 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY…………….48 DEPARTURE…….+16
TOTAL HEATING UNITS FOR THE MONTH……………565 DEPARTURE……+111
TOTAL HEATING UNITS FOR THE SEASON………….1682 DEPARTURE…….+24
TOTAL HEATING UNITS LAST SEASON TO DATE……..1428 DEPARTURE……+254
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)………..40 NW @ 01:41 P.M.
VECTOR #1 (1-Sec)……….40 NW @ 01:41 P.M.
VECTOR #2 (1-Sec)……….43 NW @ 01:47 P.M.
DAVIS #1……………….38 NNW @ 01:41 P.M.
DAVIS #2 ………………36 NNW @ 01:40 P.M.
RMY #1 (Instantaneous)…..42 NW @ 01:40 P.M.
RMY #2 (Instantaneous)…..43 NW @ 01:47 P.M.
MERLIN…………………37 NW
RICHARDS (C5C) (Inst)……39 NW @ 01:40 P.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………29 NW @ 01:43 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..27 NW @ 01:43 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..28 NW @ 01:44 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………28 NW @ 01:49 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………27 NNW @ 01:44 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..27 NW @ 01:43 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..27 NW @ 01:44 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………27 NW @ 01:43 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..15.7 NW [377 total miles]
VECTOR #1………………15.1
VECTOR #2………………16.0
DAVIS #1……………….15.8 WNW
DAVIS #2……………….15.6 NW
RMY #1…………………14.7 WNW
RMY #2…………………15.5 WNW
RICHARDS (C5C)………….15.2
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.17
TOTAL PRECIPITATION FOR THE MONTH…………..1.08 DEPARTURE…..-1.60
TOTAL PRECIPITATION FOR THE YEAR (2025)…….45.54 DEPARTURE…..-5.61
SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…..-0.4
TOTAL SNOWFALL FOR THE MONTH………………..2.4 DEPARTURE…..-2.5
TOTAL SNOWFALL FOR THE SEASON (2025-2026)…….2.5 DEPARTURE…..-4.9
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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/457/83 43 NW VEC1 43 NW RMY 44
12/9 28/9/19/-15/0.00/0.0/452/82 33 SSW VEC1 33 SSW RMY 33
12/10 46/28/37/+3/0.04/T/187/34 50 SSW VEC1 50 SSW RMY 51
12/11 37/21/29/-5/0.00/0.0/450/82 51 WNW VEC1 51 WNW RMY 53
12/12 33/18/26/-8/0.00/0.0/532/97 41 W VEC1 41 W RMY 42
12/13 34/23/29/-4/0.00/0.0/038/07 28 SW VEC1 28 SW RMY 31
12/14 31/15/23/-10/0.13/1.8/000/00 39 NNW VEC1 39 NNW RMY 40
12/15 23/10/17/-16/0.00/0.0/…/.. 40 NW VEC1 40 NW RMY 42
12/16 The low since midnight is 19F, the daily normal low is 25F.
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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 16
HIGH 61 IN 1971
LOW -2 IN 1930
PRECIP 1.88 INS. IN 2022
SNOW 8.5 INS. IN 2007
WIND 73 MPH SSE IN 1982
RECORDS FOR DECEMBER 17
HIGH 63 IN 2000
LOW -9 IN 1942
PRECIP 3.03 INS. IN 1888
SNOWFALL 15.1 INS. IN 2020
PEAK GUST 78 MPH SSE IN 2000
TODAY’S REPORT PREPARED BY: Matt Douglas
