Saturday, December 6, 2025

BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

SATURDAY, DECEMBER 6, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0659E
SUNSET:  1612E

WARMER BUT STILL WINTRY: OVERCAST SKIES WITH LIGHT SOUTHERLY WINDS….

Yesterday’s arctic air mass has moved on and has been replaced with
much more moist air. We have been under mostly overcast conditions
all day, with a few breaks in overcast offshore to our ESE-SSW. There
has been some snow observed in the area but any precipitation has
so far skirted past the observatory as of 1pm today. There were some
flakes overhead during the early morning hours but no accumulation
was reported.

This morning we observed that both Houghton and Ponkapoag ponds
were completely frozen. This is the first day of the season where both
ponds were 100% frozen. Last winter, the first day that both ponds
froze completely was on December 15th, 2024. The last time both ponds
were frozen was earlier this year on March 7th.

Temperatures have recovered quite a bit since yesterday, though it
still feels quite raw out there today. Today’s low so far of 25F was
7 degrees warmer than the average of yesterday, which was 17F. Dew
points have also increased significantly, going from negative and
single digits yesterday to the upper 20s and lower 30s today.

Winds were out of the south-southeast during the early morning hours
and have shifted to the south-southwest by late morning. Winds have
been light in the 5-10mph range throughout the day. The average speed
for the day so far is around 10mph. The peak gust so far is 20mph,
which occurred around 9:30am this morning.

Visibility has been consistent at around 30 miles throughout
the day. Visibility has been impacted today due to higher dew point
values and lingering snow showers in the vicinity.

The maximum temperature so far today is 37F degrees, which is
6 degrees below the normal high of 43F. The minimum temperature
since midnight is 25F degrees, which is 3 degrees below the normal
low of 28F.

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Today’s Observations:

7 A.M.
Weather: Overcast stratocumulus
Temperature: 30F; Dew Point: 26F; Relative Humidity: 85%
Wind: SSE @ 6 kts, wind light
Sea-level pressure: 1014.1 mb; 29.95 in. Hg: falling, then
more rapidly
Visibility: 30 miles
6-hr Max temp: 30F
6-hr Min temp: 26F
24-hr Precip: Trace
24-hr Snowfall: Trace
Snow Depth: Trace
BHO SA 1155 E3 OVC 30 141/30/26/1606/995/ WND LGT/ 8/5//
4/000 58005 6000/ 70000 10030 20026

10 A.M.
Weather: Overcast stratocumulus, few breaks in overcast
ESE-SSW
Temperature: 33F; Dew Point: 31F; Relative Humidity: 90%
Wind: S @ 9 kts
Sea-level pressure: 1013.6 mb; 29.93 in. Hg: rising, then
falling
Visibility: 30 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E5 OVC 30 136/33/31/1709/993/ FEW BINOVC ESE-SSW/
8/5// 55002

1 P.M.
Weather: Overcast stratocumulus, few breaks in overcast
ESE-S, virga N-NNE and WSW-W
Temperature: 37F; Dew Point: 33F; Relative Humidity: 84%
Wind: WSW @ 3 kts, wind light
Sea-level pressure: 1011.6 mb; 29.87 in. Hg: falling, then
more slowly
Visibility: 30 miles, thin fog N-NNE
6-hr Max temp: 37F
6-hr Min temp: 30F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: Trace
BHO SA 1755 OVC 30 116/37/33/2503/987/ FEW BINOVC ESE-S
THN F N-NNE VIRGA N-NNE AND WSW-W WND LGT/ 8/5// 4/000 56020
10037 20030

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SUMMARY FOR FRIDAY, DECEMBER 5, 2025

TEMPERATURE (DEGREES F)
MAX…….25   NORMAL…..43
MIN……..8   NORMAL…..28
MEAN……17   NORMAL…..36

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………-19
TOTAL DEPARTURE FOR THE MONTH………………………-39 [-8.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY…………….48  DEPARTURE…….+19
TOTAL HEATING UNITS FOR THE MONTH……………182  DEPARTURE…….+38
TOTAL HEATING UNITS FOR THE SEASON………….1299  DEPARTURE…….-49
TOTAL HEATING UNITS LAST SEASON TO DATE……..1115  DEPARTURE……+184

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)………..30 NW   @   02:30 A.M.
VECTOR #1 (1-Sec)……….30 NW   @   02:30 A.M.
VECTOR #2 (1-Sec)……….31 NW   @   02:24 A.M.
DAVIS #1……………….28 NW   @   02:24 A.M.
DAVIS #2 ………………29 NNW  @   02:24 A.M.
RMY #1 (Instantaneous)…..30 NW   @   02:30 A.M.
RMY #2 (Instantaneous)…..33 NW   @   02:24 A.M.
MERLIN…………………M
RICHARDS (C5C) (Inst)……29 NNW  @   02:26 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 NW   @   02:24 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19 NNW  @   12:01 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..21 NW   @   02:24 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………20 NW   @   02:30 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………21 NNW  @   02:25 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 NW   @   02:30 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..20 NW   @   02:24 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………20 NNW  @   12:01 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………7.4 SSW [178 total miles] VECTOR #1……………….8.2
VECTOR #2……………….8.6
DAVIS #1………………..8.1 WSW
DAVIS #2………………..8.1 WSW
RMY #1………………….8.1 SW
RMY #2………………….8.5 SW
RICHARDS (C5C)…………..8.5

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….TRACE DEPARTURE…..-0.19
TOTAL PRECIPITATION FOR THE MONTH…………..0.91 DEPARTURE…..+0.02
TOTAL PRECIPITATION FOR THE YEAR (2025)…….45.37 DEPARTURE…..-3.99

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………TRACE DEPARTURE…..-0.3
TOTAL SNOWFALL FOR THE MONTH………………..0.6 DEPARTURE…..-0.6
TOTAL SNOWFALL FOR THE SEASON (2025-2026)…….0.7 DEPARTURE…..-3.0

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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/…/..           37 WNW VEC1 37 WNW RMY 38
12/2  36/27/32/-5/0.85/T/…/..          38 N   VEC1 38 NNE RMY 38
12/3  37/27/32/-4/0.06/0.6/…/..        28 NW  VEC1 29 NNW RMY 30
12/4  38/15/27/T/T/…/..                60 NW  VEC1 59 WNW RMY 61
12/5  25/8/17/T/T/…/..                 30 NW  VEC1 30 NW  RMY 30

12/6 The low since midnight is 25F, the daily normal low is 28F.

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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 6
HIGH 70 IN 2001
LOW 5 IN 1901,1935
PRECIP 2.78 INS. IN 2003
SNOWFALL 17.0 INS. IN 2003
PEAK GUST 74 MPH NW IN 1981

RECORDS FOR DECEMBER 7
HIGH 74 IN 1998
LOW 6 IN 1906
PRECIP 1.67 INS. IN 1953
SNOWFALL 6.3 INS. IN 2003
PEAK GUST 76e SE IN 1976

TODAY’S REPORT PREPARED BY: Amanda Joly