Thursday, December 4, 2025

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

THURSDAY, DECEMBER 4, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0657E
SUNSET:  1612E

INTERVALS OF SUN AND CLOUDS TODAY AHEAD OF AN ARCTIC FRONT….

We started the day with some filtered sunshine, but mid level
clouds overspread the area by the mid morning hours lasting into
early this afternoon. The mid level deck was moving out right
around the 1pm observation, but numerous low level clouds were
developing to take its place. These clouds are in advance of
an arctic front that will cross the region later this afternoon,
possibly with some snow showers or squalls. Nonetheless, it will
usher in the coldest air of the season so far by tonight and
tomorrow.

Temperatures are on the “mild” side compared to where they’ll
be tomorrow, despite this, we are still running below normal
for the date. Readings rose from the upper 20s early this morning
to the mid to upper 30s by early this afternoon. Dew point values
have been holding mainly in the mid 20s through the day to this
point, but will really drop off later following the arctic front.

The wind has been fairly steady today, first out of the west-
southwest, but now more out of the west. The average speed for
the day so far is around 12mph. Gusts have been ramping up since
late this morning, frequently exceeding 25mph. The peak gust so
far is 32mph, which occurred just after 1:30pm.

Visibility has been somewhat limited today due to haziness. The
view has been stuck around 30-40 miles all day.

The maximum temperature so far today is 38F degrees, which is
6 degrees below the normal high of 44F. The minimum temperature
since midnight is 28F degrees, which is equal to the normal low
of 28F.

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Today’s Observations:

7 A.M.
Weather: Scattered altocumulus, thin broken cirrus
Temperature: 28F; Dew Point: 23F; Relative Humidity: 79%
Wind: WSW @ 9 kts
Sea-level pressure: 1013.9 mb; 29.94 in. Hg: rising, then falling
Visibility: 30 miles, hazy
6-hr Max temp: 29F
6-hr Min temp: 28F
24-hr Precip: 0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: Trace
BHO SA 1155 70 SCT E250 -BKN 30 139/28/23/2509/994/ HAZY/
8/051 4/000 58002 10029 20028

10 A.M.
Weather: Scattered altostratus, broken altocumulus
Temperature: 35F; Dew Point: 27F; Relative Humidity: 72%
Wind: WSW @ 8 kts
Sea-level pressure: 1012.7 mb; 29.91 in. Hg: falling, then more slowly
Visibility: 30 miles, hazy
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 65 SCT E100 BKN 30 127/35/27/2508/991/ HAZY/ 8/070 56012

1 P.M.
Weather: Scattered stratocumulus, broken altocumulus/altostratus,
broken cirrus
Temperature: 37F; Dew Point: 24F; Relative Humidity: 60%
Wind: W @ 15G27 kts, peak wind W 31mph at 12:53 P.M.
Sea-level pressure: 1011.2 mb; 29.86 in. Hg: falling, then more rapidly
Visibility: 40 miles, hazy
6-hr Max temp: 38F
6-hr Min temp: 28F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: Trace
BHO SA 1755 40 SCT E95 BKN 250 BKN 40 112/37/24/2815G27/986/
HAZY PK WND 2727/53/ 8/571 4/000 58015 10038 20028

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SUMMARY FOR WEDNESDAY, DECEMBER 3, 2025

TEMPERATURE (DEGREES F)
MAX…….37   NORMAL…..44
MIN…….27   NORMAL…..29
MEAN……32   NORMAL…..36

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-4
TOTAL DEPARTURE FOR THE MONTH………………………-11 [-3.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY…………….33  DEPARTURE……..+4
TOTAL HEATING UNITS FOR THE MONTH…………….96  DEPARTURE…….+11
TOTAL HEATING UNITS FOR THE SEASON………….1213  DEPARTURE…….-76
TOTAL HEATING UNITS LAST SEASON TO DATE……..1050  DEPARTURE……+163

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)………..28 NW   @   04:25 A.M.
VECTOR #1 (1-Sec)……….29 NNW  @   04:58 A.M.
VECTOR #2 (1-Sec)……….32 NNW  @   12:13 A.M.
DAVIS #1……………….26 N    @   12:02 A.M.
DAVIS #2 ………………28 N    @   12:13 A.M.
RMY #1 (Instantaneous)…..30 NNW  @   04:14 A.M.
RMY #2 (Instantaneous)…..32 NN   @   04:25 A.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)……28 NNW  @   04:14 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 NNW  @   03:40 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19 N    @   12:21 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..19 NNW  @   12:03 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 N    @   12:21 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………22 N    @   12:02 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 NNW  @   12:31 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..20 NNW  @   12:02 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………19 N    @   12:21 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.3 NW [246 total miles] VECTOR #1………………10.3
VECTOR #2………………10.8
DAVIS #1……………….10.4 NW
DAVIS #2……………….10.3 NW
RMY #1…………………10.2 NW
RMY #2…………………10.7 WNW
RICHARDS (C5C)………….10.3

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.17
TOTAL PRECIPITATION FOR THE MONTH…………..0.91 DEPARTURE…..+0.39
TOTAL PRECIPITATION FOR THE YEAR (2025)…….45.37 DEPARTURE…..-3.62

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…..-0.3
TOTAL SNOWFALL FOR THE MONTH………………..0.6 DEPARTURE…..-0.1
TOTAL SNOWFALL FOR THE SEASON (2025-2026)…….0.7 DEPARTURE…..-2.5

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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 The low since midnight is 28F, 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 4
HIGH 67 IN 1998
LOW -4 IN 1940
PRECIP 1.87 INS. IN 1968
SNOWFALL 6.0 INS. IN 1907
PEAK GUST 73 MPH WNW IN 1980

RECORDS FOR DECEMBER 5
HIGH 65 IN 2001
LOW -1 IN 1926
PRECIP 2.86 INS. IN 1993
SNOWFALL 7.0 INS. IN 1893, 1895, 1926, 1981
PEAK GUST 67 MPH WNW IN 1961, S IN 1973

TODAY’S REPORT PREPARED BY: Matt Douglas