Friday, September 19, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
FRIDAY, SEPTEMBER 19, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0529E
SUNSET: 1746E
PARTLY CLOUDY SKIES, WARM, WITH A BREEZY NORTHWEST WIND….
We started the day with mostly clear skies and as the day
progressed we saw increasing clouds make their way to the
region. It’s been a quiet, uneventful kind of day with just
a slight breeze from the northwest under mostly partly cloudy
conditions throughout much of the day.
Temperatures were quick to warm today, thanks to all the
sunshine in the beginning of the day. Overnight temperatures
only made it to around 60F, and by the afternoon we had just
made it to 80F. Dew points have remained in the lower 60’s
so not as muggy as yesterday, but still overall feeling quite
summer-like.
Winds have been predominantly out of the northwest today,
bringing much drier air to the region. The average speed for
the day so far is around 11mph. The peak gust so far for the
day is 20mph, which occurred just before 9:30am this morning.
Visibility was impacted by a smoke layer aloft this morning,
with around 40 miles. By the afternoon we had improved to
around 60 miles.
The maximum temperature so far today is 80F degrees, which is
8 degrees above the normal high of 72F. The minimum temperature
since midnight is 60F degrees, which is 5 degrees above the
normal low of 55F.
————————————————————–
Today’s Observations:
7 A.M.
Weather: Clear, few altocumulus distant ENE-E
Temperature: 65F; Dew Point: 57F; Relative Humidity: 76%
Wind: NW @ 8 kts
Sea-level pressure: 1014.0 mb; 29.94 in. Hg: rising, then more slowly
Visibility: 40 miles, smoke layer aloft all quadrants
6-hr Max temp: 65F
6-hr Min temp: 60F
24-hr Precip: 0.01 inches
BHO SA 1155 CLR 40 140/65/57/3208/994/ FEW AC DSNT ENE-E K LYR
ALF ALQDS/ 8/050 51018 70001 10065 20060
10 A.M.
Weather: Clear, few cumulus WSW-NNW-E
Temperature: 75F; Dew Point: 62F; Relative Humidity: 63%
Wind: NW @ 7 kts
Sea-level pressure: 1014.4 mb; 29.96 in. Hg: rising, then falling
Visibility: 50 miles
3-hr Precip: 0.00 inches
BHO SA 1455 CLR 50 144/75/62/3207/996/ FEW CU WSW-NNW-E/
8/200 50004
1 P.M.
Weather: Scattered cumulus
Temperature: 79F Dew Point: 59F; Relative Humidity: 50%
Wind: WNW @ 7 kts
Sea-level pressure: 1014.2 mb; 29.95 in. Hg: falling, then more rapidly
Visibility: 60 miles
6-hr Max temp: 80F
6-hr Min temp: 65F
6-hr Precip: 0.00 inches
BHO SA 1755 45 SCT 60 142/79/59/2907/995/ 8/200 58002 10080 20065
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SUMMARY FOR THURSDAY, SEPTEMBER 18, 2025
TEMPERATURE (DEGREES F)
MAX…….75 NORMAL…..72
MIN…….61 NORMAL…..55
MEAN……68 NORMAL…..63
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+5
TOTAL DEPARTURE FOR THE MONTH………………………-17 [-1.1 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..0 DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE MONTH…………….26 DEPARTURE……..-9
TOTAL HEATING UNITS FOR THE SEASON……………46 DEPARTURE……..-7
TOTAL HEATING UNITS LAST SEASON TO DATE……….21 DEPARTURE…….+25
COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..3 DEPARTURE……..+1
TOTAL COOLING UNITS FOR THE MONTH…………….34 DEPARTURE…….-26
TOTAL COOLING UNITS FOR THE SEASON…………..706 DEPARTURE…….+51
TOTAL COOLING UNITS LAST SEASON TO DATE………753 DEPARTURE…….-47
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)………..20 S @ 07:07 P.M.
VECTOR #1 (1-Sec)……….20 S @ 07:07 P.M.
VECTOR #2 (1-Sec)……….21 S @ 07:06 P.M.
DAVIS #1……………….22 S @ 07:07 P.M.
DAVIS #2 ………………23 S @ 07:07 P.M.
RMY #1 (Instantaneous)…..20 S @ 07:07 P.M.
RMY #2 (Instantaneous)…..21 S @ 07:06 P.M.
MERLIN…………………19 S
RICHARDS (C5C) (Inst)……20 S @ 07:07 P.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………13 W @ 11:51 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..13 S @ 07:08 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..13 S @ 07:08 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………13 W @ 11:51 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………17 S @ 06:24 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..13 S @ 07:08 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..14 S @ 06:32 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………13 S @ 07:08 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………5.9 NNE [142 total miles]
VECTOR #1……………….6.7
VECTOR #2……………….6.9
DAVIS #1………………..6.1 W
DAVIS #2………………..6.4 W
RMY #1………………….6.4 NW
RMY #2………………….6.8 NW
RICHARDS (C5C)…………..6.8
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.01 DEPARTURE…..-0.13
TOTAL PRECIPITATION FOR THE MONTH…………..2.58 DEPARTURE…..+0.32
TOTAL PRECIPITATION FOR THE YEAR (2025)…….33.91 DEPARTURE…..-2.96
————————————————————–
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/+1/0.00/694/89 26 SSW VEC1 27 SSW RMY 28
9/5 82/63/73/+5/0.12/404/52 30 SSW VEC1 31 SSW RMY 33
9/6 84/64/74/+6/1.05/457/59 55 W VEC1 55 W RMY 57 TSTM
9/7 64/56/60/-7/0.97/000/00 16 WNW VEC1 16 NNE RMY 15
9/8 68/49/59/-8/0.00/508/66 21 NW VEC1 21 NW RMY 24
9/9 70/53/62/-5/0.00/697/91 22 ENE VEC1 23 E RMY 23
9/10 65/54/60/-6/0.00/183/24 24 NE VEC1 25 NE RMY 25
9/11 77/51/64/-2/0.00/714/94 21 N VEC1 17 N RMY 18
9/12 71/56/64/-2/0.00/735/97 24 ENE VEC1 24 NNE RMY 23
9/13 76/55/66/+1/T/634/84 26 S VEC1 26 S RMY 25
9/14 79/57/68/+3/0.00/…/.. 15 NE VEC1 15 SW RMY 15
9/15 72/57/65/0/0.00/…/.. 20 N VEC1 19 N RMY 18
9/16 71/55/63/-1/0.00/…/.. 20 E VEC1 19 ESE RMY 19
9/17 71/55/63/-1/T/…/.. 22 E VEC1 22 E RMY 21
9/18 75/61/68/+5/0.44/…/.. 20 S VEC1 20 S RMY 20
9/19 The low since midnight is 60F, the daily normal low is 55F.
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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 19
HIGH 87F IN 1906,1983
LOW 37F IN 1929
PRECIP 3.69 INCHES IN 1936
PEAK GUST 55 MPH S IN 2012
RECORDS FOR SEPTEMBER 20
HIGH 90 IN 1983
LOW 34 IN 1979
PRECIP 4.57 INS IN 1899
PEAK GUST 44 MPH NE IN 1972
TODAY’S REPORT PREPARED BY: Amanda Joly
