Wednesday, September 10, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
WEDNESDAY, SEPTEMBER 10, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0519E
SUNSET: 1802E
MAINLY CLOUDY AND COOL WITH A BRISK ONSHORE WIND….
Today has featured mainly cloudy skies with breaks starting to
expand into the area by early this afternoon.
Temperatures continue on the cooler side with readings only
reaching the mid 60s so far today. With the brisk onshore wind
and higher relative humidity levels, it did feel rather damp
early this morning. Dew point values have generally been in the
mid 50s all day.
The wind has been on the brisk side, generally out of the north-
east. The average speed for the day so far is around 10mph. Gusts
have been exceeding 20mph at times, with a peak gust so far of
23mph, which occurred around 10:50am this morning.
Visibility hasn’t been terrible, with a view of 50-60 miles
through the day.
The maximum temperature so far today is 65F degrees, which is
10 degrees below the normal high of 75F. The minimum temperature
since midnight is 55F degrees, which is 3 degrees below the
normal low of 58F.
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Today’s Observations:
7 A.M.
Weather: Overcast altocumulus/altostratus, few breaks in overcast
distant W-NW-NE, higher clouds visible distant NNE-NE
Temperature: 58F; Dew Point: 56F; Relative Humidity: 92%
Wind: ENE @ 9G14 kts
Sea-level pressure: 1026.1 mb; 30.30 in. Hg: rising, then falling
Visibility: 50 miles
6-hr Max temp: 58F
6-hr Min temp: 55F
24-hr Precip: 0.00 inches
BHO SA 1155 E65 OVC 50 261/58/56/0609G14/030/ FEW BINOVC DSNT
W-NW-NE HIER CLDS VSBL DSNT NNE-NE/ 8/07/ 58004 10058 20055
10 A.M.
Weather: Broken stratocumulus, overcast altostratus
Temperature: 63F; Dew Point: 56F; Relative Humidity: 79%
Wind: ENE @ 8G15 kts
Sea-level pressure: 1025.5 mb; 30.28 in. Hg: falling, then more rapidly
Visibility: 50 miles
3-hr Precip: 0.00 inches
BHO SA 1455 E20 BKN 60 OVC 50 255/63/56/0608G15/028/ 8/52/ 58006
1 P.M.
Weather: Broken stratocumulus, broken altocumulus
Temperature: 64F Dew Point: 56F; Relative Humidity: 75%
Wind: NE @ 9G17 kts
Sea-level pressure: 1024.1 mb; 30.24 in. Hg: falling, then more slowly
Visibility: 60 miles
6-hr Max temp: 65F
6-hr Min temp: 58F
6-hr Precip: 0.00 inches
BHO SA 1755 E20 BKN 65 BKN 60 241/64/56/0509G17/024/ 8/550 56014
10065 20058
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SUMMARY FOR TUESDAY, SEPTEMBER 9, 2025
TEMPERATURE (DEGREES F)
MAX…….70 NORMAL…..75
MIN…….53 NORMAL…..58
MEAN……62 NORMAL…..67
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-5
TOTAL DEPARTURE FOR THE MONTH………………………-14 [-1.8 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..3 DEPARTURE……..+1
TOTAL HEATING UNITS FOR THE MONTH…………….15 DEPARTURE……..+4
TOTAL HEATING UNITS FOR THE SEASON……………35 DEPARTURE……..+6
TOTAL HEATING UNITS LAST SEASON TO DATE……….21 DEPARTURE…….+14
COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..0 DEPARTURE……..-3
TOTAL COOLING UNITS FOR THE MONTH…………….27 DEPARTURE…….-10
TOTAL COOLING UNITS FOR THE SEASON…………..699 DEPARTURE…….+67
TOTAL COOLING UNITS LAST SEASON TO DATE………716 DEPARTURE…….-17
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)………..22 ENE @ 01:25 P.M.
VECTOR #1 (1-Sec)……….23 E @ 12:40 P.M.
VECTOR #2 (1-Sec)……….22 E @ 12:46 P.M.
DAVIS #1……………….22 E @ 01:25 P.M.
DAVIS #2 ………………22 E @ 01:26 P.M.
RMY #1 (Instantaneous)…..23 ENE @ 01:25 P.M.
RMY #2 (Instantaneous)…..23 ENE @ 01:25 P.M.
MERLIN…………………21 ENE
RICHARDS (C5C) (Inst)……22 ENE @ 01:25 P.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………15 E @ 01:11 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..15 ENE @ 01:23 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17 ENE @ 01:09 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………17 E @ 01:09 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………17 E @ 01:09 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..16 E @ 01:09 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 ENE @ 01:09 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………16 E @ 01:09 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………8.7 ENE [208 total miles]
VECTOR #1……………….8.4
VECTOR #2……………….9.5
DAVIS #1………………..9.4 E
DAVIS #2………………..9.2 E
RMY #1………………….8.9 ENE
RMY #2………………….9.3 ENE
RICHARDS (C5C)…………..9.3
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH…………..2.14 DEPARTURE…..+1.08
TOTAL PRECIPITATION FOR THE YEAR (2025)…….33.47 DEPARTURE…..-2.20
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PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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
9/1 73/55/64/-5/0.00/221/28 23 NE VEC1 23 ENE RMY 23
9/2 77/58/68/-1/0.00/714/91 18 ESE VEC1 19 ESE RMY 18
9/3 78/57/68/0/0.00/719/92 21 SSW VEC1 21 SSW RMY 21
9/4 81/56/69/+1/0.00/…/.. 26 SSW VEC1 27 SSW RMY 28
9/5 82/63/73/+5/0.12/…/.. 30 SSW VEC1 31 SSW RMY 33
9/6 84/64/74/+6/1.05/…/.. 55 W VEC1 55 W RMY 57 TSTM
9/7 64/56/60/-7/0.97/…/.. 16 WNW VEC1 16 NNE RMY 15
9/8 68/49/59/-8/0.00/…/.. 21 NW VEC1 21 NW RMY 24
9/9 70/53/62/-5/0.00/…/.. 22 ENE VEC1 23 E RMY 23
9/10 The low since midnight is 55F, the daily normal low is 58F.
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SEPTEMBER 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 SEPTEMBER 10
HIGH 90F IN 1931,1989
LOW 41F IN 1956
PRECIP 5.60 INCHES IN 1999 (DAILY RECORD FOR SEPTEMBER)
PEAK GUST 48 MPH NW IN 1972
RECORDS FOR SEPTEMBER 11
HIGH 93F IN 1983, 2013
LOW 37F IN 1917
PRECIP 5.23 INCHES IN 1954 (HURRICANE EDNA)
PEAK GUST 101 MPH NW IN 1954 (HURRICANE EDNA)
TODAY’S REPORT PREPARED BY: Matt Douglas
