Thursday, December 11, 2025

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

THURSDAY, DECEMBER 11, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0703E
SUNSET:  1612E

ARCTIC FRONT PASSES THROUGH THIS MORNING USHERING IN YET ANOTHER
ROUND OF ARCTIC AIR….

I hope everyone enjoyed the reprieve from the cold weather
yesterday, because yet another arctic air mass is taking over
the region today. Light rain developed last evening ahead of
the frontal system and lasted for a few hours, however it didn’t
really amount to much with only 0.04″ measured.

The front came through this morning with clearing skies, gusty
winds, and falling temperatures following it.

The high temperature for the day occurred back around midnight
with readings in the upper 30s. They have been gradually falling
through the day with readings near 30F by the 1pm observation.
The dew point has plummeted from the mid 30s overnight to the
mid 20s by 7am this morning, to now into the upper single digits
by early this afternoon, indicative of the arctic air mass
rushing in via strong cold air advection.

The wind has been busy most of the day, but had a marked increase
in speeds just after 8:30am this morning. A west to west-northwest
flow has been averaging around 18mph for the day so far, but has
been averaging over 20mph since mid morning. Gusts have been
frequently reaching 40mph since mid morning as well with a peak
gust so far of 50mph, which occurred just after 10:30am.

Visibility has been improving as the day has progressed, rising
from around 50 miles early this morning to 70 miles by early
this afternoon.

The maximum temperature so far today is 37F degrees, which is
4 degrees below the normal high of 41F. The minimum temperature
since midnight is 30F degrees, which is 4 degrees above the
normal low of 26F.

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Today’s Observations:

7 A.M.
Weather: Overcast stratocumulus, few breaks in overcast all quadrants
Temperature: 34F; Dew Point: 26F; Relative Humidity: 72%
Wind: WNW @ 16G26 kts, peak wind WNW 30mph at 6:51 A.M.
Sea-level pressure: 995.4 mb; 29.39 in. Hg: rising, then more rapidly
Visibility: 50 miles
6-hr Max temp: 37F
6-hr Min temp: 34F
24-hr Precip: 0.04 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 E30 OVC 50 954/34/26/2916G26/939/ FEW BINOVC ALQDS
PK WND 2926/51/ 8/5// 53027 70004 10037 20034

10 A.M.
Weather: Scattered cirrus, few stratocumulus all quadrants
Temperature: 31F; Dew Point: 10F; Relative Humidity: 41%
Wind: W @ 23G36 kts, peak wind W 41mph at 9:49 A.M.
Sea-level pressure: 998.9 mb; 29.50 in. Hg: rising, then more rapidly
Visibility: 70 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 250 SCT 70 989/31/10/2823G36/950/ FEW SC ALQDS
PK WND 2836/49/ 8/501 53035

1 P.M.
Weather: Clear, few stratocumulus all quadrants, few cirrus
distant E-S-SW
Temperature: 31F; Dew Point: 8F; Relative Humidity: 36%
Wind: W @ 22G36 kts, peak wind W 41mph at 12:50 P.M.
Sea-level pressure: 999.0 mb; 29.50 in. Hg: rising, then falling
Visibility: 70 miles
6-hr Max temp: 34F
6-hr Min temp: 30F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 CLR 70 990/31/8/2822G36/950/ FEW SC ALQDS
FEW CI DSNT E-S-SW VIRGA DSNT WSW-NNW PK WND 2836/50/
8/501 50001 10034 20030

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SUMMARY FOR WEDNESDAY, DECEMBER 10, 2025

TEMPERATURE (DEGREES F)
MAX…….46   NORMAL…..42
MIN…….28   NORMAL…..27
MEAN……37   NORMAL…..34

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+3
TOTAL DEPARTURE FOR THE MONTH………………………-39 [-7.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY…………….28  DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE MONTH……………364  DEPARTURE…….+69
TOTAL HEATING UNITS FOR THE SEASON………….1481  DEPARTURE…….-18
TOTAL HEATING UNITS LAST SEASON TO DATE……..1267  DEPARTURE……+214

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)………..50 SSW  @   02:32 P.M.
VECTOR #1 (1-Sec)……….50 SSW  @   02:32 P.M.
VECTOR #2 (1-Sec)……….49 SSW  @   02:31 P.M.
DAVIS #1……………….50 S    @   02:28 P.M.
DAVIS #2 ………………53 S    @   01:08 P.M.
RMY #1 (Instantaneous)…..51 S    @   02:17 P.M.
RMY #2 (Instantaneous)…..53 SSW  @   02:31 P.M.
MERLIN…………………44 S
RICHARDS (C5C) (Inst)……47 S    @   02:17 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………36 SSW  @   02:31 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..36 SSW  @   02:31 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..37 SSW  @   02:31 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………37 S    @   02:31 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………39 S    @   02:32 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..35 SSW  @   02:31 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..37 SSW  @   02:31 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………34 SSW  @   02:31 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..17.8 SW  [426 total miles] VECTOR #1………………17.6
VECTOR #2………………18.2
DAVIS #1……………….17.3 SSW
DAVIS #2……………….18.3 SW
RMY #1…………………17.3 SSW
RMY #2…………………18.2 SSW
RICHARDS (C5C)………….16.3

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.04 DEPARTURE…..-0.14
TOTAL PRECIPITATION FOR THE MONTH…………..0.95 DEPARTURE…..-0.84
TOTAL PRECIPITATION FOR THE YEAR (2025)…….45.41 DEPARTURE…..-4.85

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…..-2.3
TOTAL SNOWFALL FOR THE SEASON (2025-2026)…….0.7 DEPARTURE…..-4.7

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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  The low since midnight is 30F, 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 11
HIGH 63 IN 1911
LOW -1 IN 1988
PRECIP 3.38 INS. IN 2024
SNOWFALL 4.8 INS. IN 2019
PEAK GUST 78 S IN 1969

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

TODAY’S REPORT PREPARED BY: Matt Douglas