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BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
TUESDAY, SEPTEMBER 15, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0524E
SUNSET: 1754E
A SPECTACULAR FALL-LIKE DAY HERE ON THE SUMMIT OF BLUE HILL….
An area of high pressure building over the northeastern U.S. is
in control of our weather today. Skies have been mainly clear
with abundant sunshine. Despite the sunshine, a nice and cool
air mass out of Canada is also over the region allowing for very
clear air, comfortable humidity levels, and cooler than normal
temperatures.
Temperatures started the day in the upper 40s and have only
recovered to the upper 60s by early this afternoon. A true taste
of fall (even though meteorologically it’s been fall since
September 1st). Dew point values started the day in the mid to
upper 40s, but have risen a bit to around 50F thanks to a light
onshore wind.
Winds are much lighter today than they were yesterday. A north
wind early this morning has veered to an easterly flow by early
this afternoon. Speeds are quite light however with the average
for the day so far around 8mph. The peak gust for the day so
far is 15mph, which occurred just before 9am this morning.
Visibility has been excellent all day with a view of around 80
miles for all 3 observations. Just a spectacular weather day!
The maximum temperature so far today is 68F, which is 5 degrees
below the normal high of 73F. The minimum temperature since
midnight is 48F, which is 8 degrees below the normal low of 56F.
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Today’s Observations:
7 A.M.
Weather: Clear, few stratocumulus distant E-S
Temperature: 53F; Dew Point: 47F; Relative Humidity: 79%
Wind: N @ 6 kts, wind light
Sea-level pressure: 1030.1 mb; 30.42 in. Hg: rising, then more rapidly
Visibility: 80 miles
6-hr Max temp: 53F
6-hr Min temp: 48F
24-hr Precip: 0.00 inches
BHO SA 1155 CLR 80 301/53/47/0106/042/ FEW SC DSNT E-S WND LGT/
8/500 53029 10053 20048
10 A.M.
Weather: Scattered stratocumulus, scattered cirrus
Temperature: 64F; Dew Point: 51F; Relative Humidity: 62%
Wind: ENE @ 5 kts, wind light and variable
Sea-level pressure: 1031.2 mb; 30.45 in. Hg: rising unsteadily
Visibility: 80 miles
3-hr Precip: 0.00 inches
BHO SA 1455 35 SCT 250 SCT 80 312/64/51/0605/045/ WND L/V/
8/501 52011
1 P.M.
Weather: Clear, few stratocumulus distant ESE-S and distant NNW-N,
few cirrus all quadrants
Temperature: 66F; Dew Point: 51F; Relative Humidity: 57%
Wind: ENE @ 3 kts, wind light and variable
Sea-level pressure: 1029.7 mb; 30.41 in. Hg: falling, then more slowly
Visibility: 80 miles
6-hr Max temp: 66F
6-hr Min temp: 53F
6-hr Precip: 0.00 inches
BHO SA 1755 CLR 80 297/66/51/0703/041/ FEW SC DSNT ESE-S AND
DSNT NNW-N FEW CI ALQDS WND L/V/ 8/501 56015 10066 20053
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SUMMARY FOR MONDAY, SEPTEMBER 14, 2026
TEMPERATURE (DEGREES F)
MAX…….72 NORMAL…..74
MIN…….53 NORMAL…..56
MEAN……63 NORMAL…..65
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-2
TOTAL DEPARTURE FOR THE MONTH (SEP)…………………..0 [-0.2 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2026 THRU JUN 2027)
TOTAL HEATING UNITS FOR YESTERDAY……………..2 DEPARTURE……..-1
TOTAL HEATING UNITS FOR THE MONTH (SEP)………..9 DEPARTURE…….-14
TOTAL HEATING UNITS FOR THE SEASON……………12 DEPARTURE…….-29
TOTAL HEATING UNITS LAST SEASON TO DATE……….42 DEPARTURE…….-30
COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..0 DEPARTURE……..-3
TOTAL COOLING UNITS FOR THE MONTH (SEP)……….38 DEPARTURE…….-13
TOTAL COOLING UNITS FOR THE SEASON…………..792 DEPARTURE……+145
TOTAL COOLING UNITS LAST SEASON TO DATE………703 DEPARTURE…….+89
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)………..32 NNW @ 12:09 P.M.
VECTOR #1 (1-Sec)……….32 NNW @ 12:09 P.M.
VECTOR #2 (1-Sec)……….34 NW @ 08:45 A.M.
DAVIS #1……………….31 WNW @ 10:44 A.M.
DAVIS #2 ………………29 NNW @ 08:45 A.M.
RMY #1 (Instantaneous)…..34 NNW @ 10:51 A.M.
RMY #2 (Instantaneous)…..34 NW @ 08:31 A.M.
MERLIN…………………32 N
RICHARDS (C5C) (Inst)……33 NNW @ 12:09 P.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………23 NW @ 12:23 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..21 NNW @ 10:46 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..22 NW @ 11:34 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 NW @ 10:46 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………21 NNW @ 08:35 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..21 NNW @ 10:46 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..21 NW @ 11:34 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………21 NNW @ 10:46 A.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….12.6 NW [302 total miles]
VECTOR #1……………..12.5
VECTOR #2……………..13.0
DAVIS #1………………12.8 NW
DAVIS #2………………12.3 NNW
RMY #1………………..12.3 NW
RMY #2………………..12.6 NW
RICHARDS (C5C)…………12.7
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.13
TOTAL PRECIPITATION FOR THE MONTH (SEP)……..2.01 DEPARTURE…..+0.31
TOTAL PRECIPITATION FOR THE YEAR (2026)…….28.00 DEPARTURE…..-8.31
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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 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/…/.. 44 W VEC1 43 W RMY 47
9/11 77/59/68/+2/0.00/…/.. 23 NW VEC1 23 NW RMY 25
9/12 77/55/66/0/0.00/…/.. 23 SSW VEC1 23 SSW RMY 22
9/13 67/60/64/-1/0.98/…/.. 25 SE VEC1 26 SE RMY 24
9/14 72/53/63/-2/T/…/.. 32 NNW VEC1 32 NNW RMY 34
9/15 The low since midnight is 48F, the daily normal low is 56F.
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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 15
HIGH 89F IN 1931
LOW 35F IN 1913
PRECIP 3.93 INCHES IN 1904 (Extra-tropical storm making landfall
in New England on 9/15/1904 passing east of BHO and bringing a
storm total of 4.11 inches 9/14-15/1904)
PEAK GUST 65e MPH NW IN 1944 (In the wake of Great Atlantic Hurricane)
RECORDS FOR SEPTEMBER 16
HIGH 91F IN 1939,1941
LOW 39F IN 1984
PRECIP 5.12 INCHES IN 1933 (Hurricane)
PEAK GUST 59 MPH SSE IN 1999
TODAY’S REPORT PREPARED BY: Matt Douglas
