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BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
MONDAY, SEPTEMBER 21, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0531E
SUNSET: 1743E
EARLY CLOUDS, DRIZZLE, AND FOG MAKE WAY FOR PARTIAL SUNSHINE;
BRISK AND COOL TODAY WITH AN ONSHORE WIND….
We started the day with drizzle and fog which pretty quickly
lifted early this morning, followed by breaking clouds and partial
sunshine for the balance of the day so far. High pressure building
to our north is responsible for pushing drier air down from
Canada, thus allowing for a rather decent, albeit chilly, day
across the area.
Total rainfall from the system yesterday and overnight came out to
be 0.22″. Not a big dose of rain, but every little bit helps. The
deficit for both the month and year remain intact for now at -0.30″
and -8.92″ respectively.
Temperatures continue to struggle to rise today despite the sun.
Readings have only risen into the mid 60s by early this afternoon
after starting the day in the low 50s. Dew point values remain
somewhat “elevated” thanks to the wind off the ocean with readings
in the low 50s.
Winds have been fairly steady today with some occasional gusts
exceeding 20mph. A northerly wind around midnight has gradually
veered around to the east-northeast by early this afternoon. The
average speed for the day so far is around 10mph. The peak gust
for the day so far is 23mph, which occurred just after 11:45am
this morning.
Visibility was limited early this morning due to fog, but quickly
improved once the cloud deck lifted. The view went from 1/4 of
a mile prior to the 7am observation to around 70 miles by the mid
to late morning hours, and where it remains early this afternoon.
The maximum temperature so far today is 64F, which is 7 degrees
below the normal high of 71F. The minimum temperature since
midnight is 51F, which is 3 degrees below the normal low of 54F.
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Today’s Observations:
7 A.M.
Weather: Broken stratus fractus, overcast stratus, few lower stratus
fractus all quadrants
Temperature: 51F; Dew Point: 51F; Relative Humidity: 100%
Wind: NNE @ 9G17 kts
Sea-level pressure: 1019.4 mb; 30.10 in. Hg: rising, then more rapidly
Visibility: 30 miles, occasionally lower
6-hr Max temp: 57F
6-hr Min temp: 51F
24-hr Precip: 0.22 inches
BHO SA 1155 E2 BKN 20 OVC 30 194/51/51/0209G17/010/ FEW LWR STFRA ALQDS
STFRA OCNLY DRFTG OVR SMT THN F ALQDS L-E04 VSBY OCNLY LWR ALQDS/ 8/6//
53020 6008/ 70022 10057 20051
10 A.M.
Weather: Broken stratocumulus, broken cirrus
Temperature: 60F; Dew Point: 52F; Relative Humidity: 75%
Wind: ENE @ 9G17 kts
Sea-level pressure: 1021.2 mb; 30.16 in. Hg: rising, then more slowly
Visibility: 70 miles
3-hr Precip: 0.00 inches
BHO SA 1455 E20 BKN 250 BKN 70 212/60/52/0609G17/016/ 8/501 51018
1 P.M.
Weather: Broken cirrus, few stratocumulus all quadrants
Temperature: 63F; Dew Point: 51F; Relative Humidity: 64%
Wind: NE @ 10G18 kts
Sea-level pressure: 1020.9 mb; 30.15 in. Hg: steady, then falling
Visibility: 70 miles
6-hr Max temp: 64F
6-hr Min temp: 51F
6-hr Precip: 0.00 inches
BHO SA 1755 E250 BKN 70 209/63/51/0510G18/015/ FEW SC ALQDS/
8/501 58003 10064 20051
————————————————————–
SUMMARY FOR SUNDAY, SEPTEMBER 20, 2026
TEMPERATURE (DEGREES F)
MAX…….61 NORMAL…..71
MIN…….51 NORMAL…..54
MEAN……56 NORMAL…..63
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-7
TOTAL DEPARTURE FOR THE MONTH (SEP)………………….-3 [-0.4 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2026 THRU JUN 2027)
TOTAL HEATING UNITS FOR YESTERDAY……………..9 DEPARTURE……..+5
TOTAL HEATING UNITS FOR THE MONTH (SEP)……….33 DEPARTURE…….-10
TOTAL HEATING UNITS FOR THE SEASON……………36 DEPARTURE…….-25
TOTAL HEATING UNITS LAST SEASON TO DATE……….52 DEPARTURE…….-16
COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..0 DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE MONTH (SEP)……….51 DEPARTURE…….-12
TOTAL COOLING UNITS FOR THE SEASON…………..805 DEPARTURE……+146
TOTAL COOLING UNITS LAST SEASON TO DATE………710 DEPARTURE…….+95
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)………..21 SSE @ 03:53 P.M.*
VECTOR #1 (1-Sec)……….22 SSE @ 03:47 P.M.
VECTOR #2 (1-Sec)……….20 SSE @ 03:40 P.M.
DAVIS #1……………….20 S @ 03:03 P.M.
DAVIS #2 ………………20 S @ 02:52 P.M.
RMY #1 (Instantaneous)…..21 SSE @ 03:47 P.M.
RMY #2 (Instantaneous)…..21 SE @ 03:58 P.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)……20 SSE @ 03:53 P.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………14 SSE @ 03:50 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..15 SSE @ 03:48 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..15 SSE @ 03:42 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………14 SSE @ 03:48 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………14 SSE @ 04:00 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..14 SSE @ 03:49 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..15 SSE @ 03:42 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………14 SSE @ 03:49 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..7.2 SSE [172 total miles]
VECTOR #1………………8.4
VECTOR #2………………8.9
DAVIS #1……………….7.5 SE
DAVIS #2……………….7.7 SSE
RMY #1…………………8.3 SSE
RMY #2…………………9.0 SE
RICHARDS (C5C)………….8.6
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.22 DEPARTURE…..+0.07
TOTAL PRECIPITATION FOR THE MONTH (SEP)……..2.26 DEPARTURE…..-0.30
TOTAL PRECIPITATION FOR THE YEAR (2026)…….28.25 DEPARTURE…..-8.92
————————————————————–
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 69/57/63/-6/0.21/008/01 15 SSW VEC1 15 E RMY 14
9/2 76/58/67/-2/0.00/393/50 21 ESE VEC1 21 ESE RMY 20
9/3 74/60/67/-1/0.45/196/25 24 SSE VEC1 24 SSE RMY 23
9/4 84/63/74/+6/0.00/624/80 24 NNW VEC1 25 NNW RMY 24
9/5 71/60/66/-2/T/412/53 24 ENE VEC1 24 ENE RMY 25
9/6 69/53/61/-7/0.35/364/47 24 NE VEC1 24 NNE RMY 27
9/7 79/52/66/-1/0.00/732/95 30 NW VEC1 30 NW RMY 30
9/8 80/58/69/+2/0.00/546/71 23 WNW VEC1 22 NNW RMY 24
9/9 80/58/69/+2/0.02/130/17 36 SSW VEC1 36 SSW RMY 36
9/10 84/67/76/+10/T/641/84 44 W VEC1 43 W RMY 47
9/11 77/59/68/+2/0.00/654/86 23 NW VEC1 23 NW RMY 25
9/12 77/55/66/0/0.00/667/88 23 SSW VEC1 23 SSW RMY 22
9/13 67/60/64/-1/0.98/000/00 25 SE VEC1 26 SE RMY 24
9/14 72/53/63/-2/T/572/76 32 NNW VEC1 32 NNW RMY 34
9/15 68/48/58/-7/0.00/727/97 18 S VEC1 18 SE RMY 18
9/16 78/53/66/+2/0.00/522/70 21 SW VEC1 21 WSW RMY 21
9/17 82/63/73/+9/0.03/…/.. 25 SW VEC1 25 SW RMY 27
9/18 79/58/69/+6/T/…/.. 26 N VEC1 26 NNW RMY 27
9/19 63/50/57/-6/0.00/…/.. 21 N VEC1 20 N RMY 20
9/20 61/51/56/-7/0.11/…/.. 21 SSE VEC1 22 SSE RMY 21
9/21 The low since midnight is 51F, the daily normal low is 54F.
————————————————————–
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 21
HIGH 91 IN 1895
LOW 35 IN 1929, 1956, 1962
PRECIP 5.58 INS IN 1961 (HURRICANE ESTHER; RETURNED AS TS SEPT 25-26TH)
PEAK GUST 186 MPH S IN 1938 (GREAT NEW ENGLAND HURRICANE; CALCULATED GUST, STATION RECORD)
RECORDS FOR SEPTEMBER 22
HIGH 90F IN 1895, 1914
LOW 30F IN 1904 (Earliest freeze)
PRECIP 1.16 INCHES IN 2001
PEAK GUST 60 MPH SSW IN 1989
TODAY’S REPORT PREPARED BY: Matt Douglas
