Tuesday, January 21, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
TUESDAY, JANUARY 21, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0707E
SUNSET: 1645E
ARCTIC AIR MASS CONTINUES WITH VERY COLD TEMPERATURES….
A clear sky early this morning has been overtaken by mainly high clouds
into early this afternoon. Some very filtered sunshine is still being
observed, but it’s doing very little to help warm things up today.
Temperatures dropped to 6F this morning here on the summit, but some
locations in the lower elevations got below zero. Readings have only
recovered to the mid-upper teens by early this afternoon. Dew point
values have ranged between 0F and 5F through the day, very much
indicative of an arctic air mass in place over the region.
The wind hasn’t been overly strong, but it has been a fairly steady
breeze out of the west. Despite the relatively light speed, with the
very cold air in place, wind chill values have only risen into the single
digits above zero, after dropping as low as -11F early this morning. The
average speed for the day so far is around 11mph. The peak gust, which
occurred at 10:07am this morning, was 21mph.
Visibility has been somewhat limited by some haziness, which isn’t
uncommon in very cold air masses. The view has generally been between
40-60 miles today.
The maximum temperature for today is 18F degrees, which is 16 degrees
below the normal high of 34F. The minimum temperature since midnight
is 6F degrees, which is 11 degrees below the normal low of 17F.
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Today’s Observations:
7 A.M.
Weather: Clear, few stratocumulus offshore distant NE-SE-S,
few cirrostratus distant E-S-SW, few cirrus distant W-WNW
Temperature: 6F; Dew Point: 0F; Relative Humidity: 77%
Wind: W @ 8 kts
Sea-level pressure: 1032.5 mb; 30.49 in. Hg: rising, then more rapidly
Visibility: 40 miles
6-hr Max temp: 8F
6-hr Min temp: 6F
24-hr Precip: 0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 5 inches
BHO SA 1155 CLR 40 325/6/0/2608/049/ FEW SC OFFSHR DSNT NE-SE-S
FEW CS DSNT E-S-SW FEW CI DSNT W-WNW/ 8/508 4/005 53014 10008 20006
10 A.M.
Weather: Broken cirrostratus, broken cirrus, few stratocumulus offshore
distant NE-SE-SSW
Temperature: 14F; Dew Point: 4F; Relative Humidity: 64%
Wind: W @ 7 kts
Sea-level pressure: 1034.1 mb; 30.54 in. Hg: rising, then more slowly
Visibility: 50 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E200 BKN 250 BKN 50 341/14/4/2707/054/ FEW SC OFFSHR
DSNT NE-SE-SSW/ 8/506 51016
1 P.M.
Weather: Overcast altostratus, few stratocumulus offshore distant NE-SSE
Temperature: 17F; Dew Point: 4F; Relative Humidity: 56%
Wind: W @ 7 kts, wind SW variable WNW
Sea-level pressure: 1030.9 mb; 30.44 in. Hg: falling, then more rapidly
Visibility: 60 miles
6-hr Max temp: 18F
6-hr Min temp: 6F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 5 inches
BHO SA 1755 E110 OVC 60 309/17/4/2607/044/ FEW SC OFFSHR DSNT NE-SSE
WND 23V29/ 8/51/ 4/005 58032 10018 20006
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SUMMARY FOR MONDAY, JANUARY 20, 2025
TEMPERATURE (DEGREES F)
MAX…….27 NORMAL…..34
MIN……..9 NORMAL…..18
MEAN……18 NORMAL…..26
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………..-8
TOTAL DEPARTURE FOR THE MONTH……………………..+2 [-0.1 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………47 DEPARTURE……..+8
TOTAL HEATING UNITS FOR THE MONTH…………..759 DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE SEASON…………2691 DEPARTURE……-281
TOTAL HEATING UNITS LAST SEASON TO DATE…….2598 DEPARTURE…….+93
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
F420C (Official)………..32 NW @ 01:53 P.M.
VECTOR #1 (1-Sec)……….32 NW @ 06:32 A.M.
VECTOR #2 (1-Sec)……….33 NW @ 10:03 A.M.
DAVIS #1……………….32 W @ 06:32 A.M.
DAVIS #2 ………………31 NNW @ 10:03 A.M.
RMY #1 (Instantaneous)…..36 NW @ 01:50 P.M.
RMY #2 (Instantaneous)…..33 NW @ 10:03 A.M.
MERLIN…………………30 NW
RICHARDS (C5C) (Inst)…..OTS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………23 NW @ 07:51 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..22 @ 01:46 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..23 @ 01:32 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………23 WNW @ 01:46 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………23 WNW @ 01:32 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 NW @ 04:44 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..22 WNW @ 01:32 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.7 NW [329 total miles]
VECTOR #1………………13.4
VECTOR #2………………14.4
DAVIS #1……………….13.7 WNW
DAVIS #2……………….13.8 NW
RMY #1…………………13.2 WNW
RMY #2…………………14.1 WNW
RICHARDS (C5C)…………..OTS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.13
TOTAL PRECIPITATION FOR THE MONTH…………..1.52 DEPARTURE…..-1.45
TOTAL PRECIPITATION FOR THE YEAR (2025)……..1.52 DEPARTURE…..-1.45
SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……-0.6
TOTAL SNOWFALL FOR THE MONTH………………..7.4 DEPARTURE……-4.1
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……20.0 DEPARTURE……-6.6
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PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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
1/1 47/36/42/+13/0.55/0.0/000/00 44 W VEC1 45 W RMY 44
1/2 42/31/37/+9/T/T/534/97 60 W VEC1 60 WNW RMY 63
1/3 36/26/31/+3/0.00/0.0/446/81 48 W VEC1 48 W RMY 51
1/4 29/22/26/-2/0.00/0.0/453/82 43 NW VEC1 43 NW RMY 48
1/5 32/18/25/-3/0.00/0.0/088/16 39 WNW VEC1 39 WNW RMY 40
1/6 23/15/19/-9/0.00/0.0/000/00 31 NNW VEC1 31 NNW RMY 31
1/7 24/11/18/-9/T/T/450/81 43 WNW VEC1 42 WNW RMY 47
1/8 27/14/21/-6/0.00/0.0/550/99 48 WNW VEC1 48 WNW RMY 52
1/9 25/13/19/-8/T/T/223/40 46 NW VEC1 47 NW RMY 51
1/10 40/19/30/+3/0.00/0.0/560/100 39 NW VEC1 39 NW RMY 42
1/11 30/21/26/-1/0.12/1.7/000/00 25 NW VEC1 26 NW RMY 28
1/12 36/19/28/+1/0.00/0.0/556/99 35 NNW VEC1 35 NNW RMY 39
1/13 39/26/33/+7/0.00/0.0/192/34 26 WNW VEC1 27 WNW RMY 27
1/14 32/20/26/0/0.00/0.0/537/95 44 WNW VEC1 44 WNW RMY 45
1/15 29/16/23/-3/0.00/0.0/504/89 37 NW VEC1 37 NW RMY 38
1/16 30/13/22/-4/T/T/…/.. 20 W VEC1 20 SSW RMY 20
1/17 35/16/26/0/T/T/…/.. 20 S VEC1 20 SSW RMY 20
1/18 44/27/36/+10/0.26/0.0/…/.. 36 S VEC1 37 S RMY 39
1/19 43/27/35/+9/0.51/4.6/…/.. 26 N VEC1 28 NNW RMY 29
1/20 27/9/18/-8/0.08/1.1/…/.. 32 NW VEC1 32 NW RMY 36
1/21 The low since midnight is 6F, the daily normal low is 17F.
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JANUARY 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 JANUARY 21
HIGH 65F IN 1906
LOW -4F IN 1888
PRECIP 2.49 INS. IN 1979
SNOWFALL 9.0 INS. IN 2014
PEAK GUST 78e MPH SE IN 1979
RECORDS FOR JANUARY 22
HIGH 59F IN 1916
LOW -8F IN 1888,1976
PRECIP 1.24 INS. IN 1891,1987
SNOWFALL 10.0 INS. IN 2005
PEAK GUST 67 MPH W IN 1976
TODAY’S REPORT PREPARED BY: Matt Douglas
