Tuesday, December 30, 2025

Agreement required — click “Accept & Continue” below to review and accept the Data Use & Privacy Policy

Access to this content requires acceptance of our Data Use & Privacy Policy.

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

TUESDAY, DECEMBER 30, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0713E
SUNSET: 1621E

ANOTHER ARCTIC BLAST OVERTAKES THE REGION SENDING TEMPERATURES
BACK BELOW NORMAL….

An arctic front crossed the area during the evening yesterday
accompanied by some mixed rain and sleet and a burst of wind
to 53mph. Temperatures rapidly fell with the front from the
low to mid 40s to the mid 30s within an hour! Thereafter the
temperature continued to steadily fall reaching a low of 20F
by early this morning. A few snow showers pushed through
during the late evening as well thanks to a long lake effect
streamer off Lake Erie.

Today featured some sunshine this morning, but clouds quickly
filled in as the day progressed thanks to surface “heating”
causing convective clouds to form. It has also been quite
windy today as the pressure gradient remains tight between
the bombed out low over eastern Canada and high pressure
attempting to build in from the southwest.

Temperatures are back to being well below normal today.
Readings have only managed to rise 4-5F degrees from the morning
low with the high so far in the mid 20s. Dew point values have
been holding in the single digits all day, indicating that the
air mass is indeed of Arctic origin.

As mentioned, the wind has been very busy today. A westerly
flow has been averaging at around 25mph for the day so far.
Gusts have frequently been exceeding 40mph, pretty much since
last evening. The peak gust for the day so far is 59mph, which
occurred just after 4am this morning.

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

The maximum temperature so far today is 25F degrees, which is
12 degrees below the normal high of 37F. The minimum temperature
since midnight is 20F degrees, which is 1 degree below the
normal low of 21F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Scattered stratocumulus, scattered altocumulus
Temperature: 20F; Dew Point: 7F; Relative Humidity: 55%
Wind: W @ 20G35 kts, peak wind W 40 mph at 6:49 A.M.
Sea-level pressure: 997.5 mb; 29.46 in. Hg: rising, then more rapidly
Visibility: 50 miles
6-hr Max temp: 28F
6-hr Min temp: 20F
24-hr Precip: 0.40 inches
24-hr Snowfall: Trace
Snow Depth: 0 inches
BHO SA 1155 35 SCT 75 SCT 50 975/20/7/2820G35/946/ PK WND 2835/49/
8/550 53034 70040 10028 20020

10 A.M.
Weather: Broken stratocumulus
Temperature: 24F; Dew Point: 8F; Relative Humidity: 48%
Wind: W @ 26G42 kts, peak wind WNW 48 mph at 9:53 A.M.
Sea-level pressure: 998.8 mb; 29.50 in. Hg: rising unsteadily
Visibility: 60 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E45 BKN 60 988/24/8/2826G42/950/ PK WND 2942/53/
8/500 52013

1 P.M.
Weather: Overcast stratocumulus, few breaks in overcast all
quadrants, virga all quadrants
Temperature: 24F; Dew Point: 7F; Relative Humidity: 46%
Wind: W @ 25G37 kts, peak wind W 51mph at 11:57 A.M.
Sea-level pressure: 998.9 mb; 29.50 in. Hg: rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 25F
6-hr Min temp: 20F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: Trace
BHO SA 1755 E50 OVC 70 989/24/7/2825G37/950/ FEW BINOVC ALQDS
VIRGA ALQDS PK WND 2844/57/ 8/5// 51001 10025 20020

————————————————————–

SUMMARY FOR MONDAY, DECEMBER 29, 2025

TEMPERATURE (DEGREES F)
MAX…….47 NORMAL…..37
MIN…….29 NORMAL…..21
MEAN……38 NORMAL…..29

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+9
TOTAL DEPARTURE FOR THE MONTH……………………..-112 [-4.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY…………….27 DEPARTURE……..-9
TOTAL HEATING UNITS FOR THE MONTH…………..1045 DEPARTURE……+111
TOTAL HEATING UNITS FOR THE SEASON………….2162 DEPARTURE…….+25
TOTAL HEATING UNITS LAST SEASON TO DATE……..1896 DEPARTURE……+266

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)………..53 W @ 07:14 P.M.
VECTOR #1 (1-Sec)……….50 W @ 07:14 P.M.
VECTOR #2 (1-Sec)……….56 W @ 07:14 P.M.
DAVIS #1……………….52 W @ 07:14 P.M.
DAVIS #2 ………………50 WNW @ 07:14 P.M.
RMY #1 (Instantaneous)…..53 W @ 07:14 P.M.
RMY #2 (Instantaneous)…..56 W @ 07:14 P.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)……51 WNW @ 11:20 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………36 WNW @ 11:22 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..34 WNW @ 11:22 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..39 WNW @ 11:23 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………36 W @ 11:22 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………39 WNW @ 11:22 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..32 WNW @ 11:22 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..38 WNW @ 11:23 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………34 WNW @ 11:22 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..16.2 SSW [388 total miles] VECTOR #1………………15.9
VECTOR #2………………16.7
DAVIS #1……………….15.6 SW
DAVIS #2……………….16.9 SW
RMY #1…………………15.5 SW
RMY #2…………………16.8 SSW
RICHARDS (C5C)………….15.5

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.40 DEPARTURE…..+0.24
TOTAL PRECIPITATION FOR THE MONTH…………..2.73 DEPARTURE…..-2.34
TOTAL PRECIPITATION FOR THE YEAR (2025)…….47.19 DEPARTURE…..-6.35

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………TRACE DEPARTURE…..-0.5
TOTAL SNOWFALL FOR THE MONTH………………..6.8 DEPARTURE…..-4.7
TOTAL SNOWFALL FOR THE SEASON (2025-2026)…….6.9 DEPARTURE…..-7.1

————————————————————–

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/-16/0.00/0.0/496/91 40 NW VEC1 40 NW RMY 42
12/16 36/19/28/-4/0.00/0.0/437/80 29 SW VEC1 29 SW RMY 30
12/17 45/25/35/+3/0.00/0.0/196/36 43 SW VEC1 42 SW RMY 43
12/18 47/32/40/+8/0.00/0.0/539/99 32 S VEC1 32 S RMY 34
12/19 58/32/45/+13/0.60/T/000/00 79 S VEC1 79 S RMY 81
12/20 36/27/32/+1/0.00/0.0/446/82 46 WNW VEC1 46 WNW RMY 45
12/21 45/28/37/+6/0.00/0.0/480/88 46 SSW VEC1 46 SSW RMY 46
12/22 31/22/27/-4/0.00/0.0/539/99 44 NW VEC1 44 NW RMY 44
12/23 35/26/31/0/0.19/0.8/000/00 20 SE VEC1 18 SSE RMY 19
12/24 36/24/30/0/0.03/T/180/33 50 NNW VEC1 49 NNW RMY 52
12/25 38/16/27/-3/T/T/…/.. 55 NNW VEC1 55 NNW RMY 60
12/26 21/8/15/-15/0.09/1.4/…/.. 33 NNW VEC1 33 NNW RMY 34
12/27 25/14/20/-10/0.14/2.2/…/.. 23 N VEC1 23 N RMY 24
12/28 36/14/25/-4/0.04/0.0/…/.. 26 SSW VEC1 26 SSW RMY 26
12/29 47/29/38/+9/0.58/T/…/.. 53 W VEC1 50 W RMY 53