Friday, December 5, 2025

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

FRIDAY, DECEMBER 5, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0658E
SUNSET:  1612E

ARCTIC AIR MASS MAINTAINS FREEZING CONDITIONS DESPITE SUNNY SKIES….

As promised, cold, arctic air was delivered to the region last
night and into the early morning hours. Blue Hill received a trace
of snow and liquid precipitation during the passage of the front
yesterday evening. Today’s skies have been mostly sunny with thinly
scattered mid level clouds for much of the day, providing us ample
sunshine. While the sunshine is great, it hasn’t done much to warm
up the area, as we are well under expected normal temperatures for
this time of year.

Temperatures took quite a dramatic dip as the arctic front came
through last night. With our peak gust of 60mph occurring at
7:23pm, temperatures tanked into the teens by midnight and continued
to plummet into single digits before sunrise. Our low for the day
is 8F, which occurred before 6am and is still not a record
(-1 in 1926). Temperatures have recovered with all day sunshine
and light winds, but we still have not hit above the freezing mark
as of 1pm. With all of this dry, cold air, dew points were in the
negative temperatures until just after noon where they have been in
the 1-2F degree range.

The wind was quite gusty yesterday evening and into the overnight
with the passing of the arctic front. Since then, winds have been
significantly lighter and even calm during the mid morning. Winds
have been generally out of the south-southwest for much of the
morning and early afternoon hours. The average speed for the day
so far is around 8mph. The peak gust so far is 30mph, which occurred
around 2:30am this morning.

Visibility has been consistent at around 60 miles throughout
the day.

The maximum temperature so far today is 25F degrees, which is
18 degrees below the normal high of 43F. The minimum temperature
since midnight is 8F degrees, which is 20 degrees below the normal
low of 28F.

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Today’s Observations:

7 A.M.
Weather: Thinly scattered altocumulus, few stratocumulus
distant ENE-SE-SSW
Temperature: 9F; Dew Point: -1F; Relative Humidity: 64%
Wind: NW @ 8 kts
Sea-level pressure: 1027.0 mb; 30.33 in. Hg: rising, then
falling
Visibility: 60 miles
6-hr Max temp: 15F
6-hr Min temp: 8F
24-hr Precip: Trace
24-hr Snowfall: Trace
Snow Depth: Trace
BHO SA 1155 190 -SCT 60 270/9/-1/3108/033/ FEW SC DSNT
ENE-SE-SSW/ 8/550 4/000 50005 70000 10015 20008

10 A.M.
Weather: Clear, few stratocumulus distant ENE-SE-SSW,
few altocumulus SE-SSE
Temperature: 17F; Dew Point: -3F; Relative Humidity: 42%
Wind: Calm
Sea-level pressure: 1027.0 mb; 30.33 in. Hg: rising, then
falling
Visibility: 60 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 60 270/17/-3/0000/033/ FEW SC DSNT ENE-SE-SSW
FEW AC SE-SSE WND CALM/ 8/550 50000

1 P.M.
Weather: Thinly scattered altocumulus, few stratocumulus
distant ENE-SE-SSW
Temperature: 25F; Dew Point: 2F; Relative Humidity: 37%
Wind: SSW @ 6 kts, wind light
Sea-level pressure: 1023.9 mb; 30.24 in. Hg: falling, then
more rapidly
Visibility: 60 miles
6-hr Max temp: 25F
6-hr Min temp: 9F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: Trace
BHO SA 1755 190 -SCT 60 239/25/2/2006/024/ FEW SC DSNT
ENE-SE-SSW WND LGT/ 8/550 4/000 58031 10025 20009

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SUMMARY FOR THURSDAY, DECEMBER 4, 2025

TEMPERATURE (DEGREES F)
MAX…….38   NORMAL…..43
MIN…….15   NORMAL…..28
MEAN……27   NORMAL…..36

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-9
TOTAL DEPARTURE FOR THE MONTH………………………-20 [-5.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY…………….38  DEPARTURE……..+9
TOTAL HEATING UNITS FOR THE MONTH……………134  DEPARTURE…….+20
TOTAL HEATING UNITS FOR THE SEASON………….1251  DEPARTURE…….-67
TOTAL HEATING UNITS LAST SEASON TO DATE……..1084  DEPARTURE……+167

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)………..60 NW   @   07:23 P.M.
VECTOR #1 (1-Sec)……….59 WNW  @   07:22 P.M.
VECTOR #2 (1-Sec)……….62 WNW  @   07:21 P.M.
DAVIS #1……………….56 WNW  @   07:19 P.M.
DAVIS #2 ………………59 NW   @   07:21 P.M.
RMY #1 (Instantaneous)…..61 WNW  @   07:21 P.M.
RMY #2 (Instantaneous)…..63 WNW  @   07:21 P.M.
MERLIN…………………56 NW
RICHARDS (C5C) (Inst)……58 WNW  @   07:21 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………37 NW   @   07:23 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..38 NW   @   07:23 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..45 WNW  @   07:23 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………41 WNW  @   07:27 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………44 NW   @   07:23 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..37 NW   @   07:23 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..43 WNW  @   07:23 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………39 WNW  @   07:27 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..16.0 W [385 total miles] VECTOR #1………………15.5
VECTOR #2………………16.5
DAVIS #1……………….16.0 W
DAVIS #2……………….16.3 WNW
RMY #1…………………15.0 W
RMY #2…………………16.1 W
RICHARDS (C5C)………….15.3

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….TRACE 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…………TRACE 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  38/15/27/T/T/…/..                60 NW  VEC1 59 WNW RMY 61

12/5 The low since midnight is 8F, 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 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

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

TODAY’S REPORT PREPARED BY: Amanda Joly