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BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SATURDAY, SEPTEMBER 12, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0521E
SUNSET: 1759E
A SPLENDID FALL DAY WITH PLENTY OF SUNSHINE, SEASONABLE TEMPERATURES,
AND COMFORTABLE HUMIDITY LEVELS….
We’ve lucked out once again with another spectacular weekend day
as skies were mainly clear through the morning, with only some
high thin cirrus clouds starting to increase this afternoon. With
temperatures near seasonable levels (actually just a touch above)
and continued comfortable humidity levels, it’s been a great day
to get outside and enjoy any activities.
Temperatures started the day in the mid 50s and have recovered
to the mid to upper 70s by early this afternoon. Normal highs
for mid September should be in the mid 70s. Dew point values
have remained in the low 50s throughout the day, thus giving
us a very comfortable feel out there.
Winds have returned to being on the light side as it has slowly
veered from the north, through east, to finally the south-
southwest. This shift of the wind to a southerly direction is
the first sign of a pending change in the air mass coming
overnight tonight and tomorrow. The average speed for the day
so far is around 7mph. The peak gust for the day so far is 16mph,
which occurred just before 1pm this afternoon.
Visibility has been holding at around 40 miles all day due to
general haziness, likely residual pollution from the inversion
early this morning.
The maximum temperature so far today is 77F, which is 3 degrees
above the normal high of 74F. The minimum temperature since
midnight is 55F, which is 2 degrees below the normal low of 57F.
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Today’s Observations:
7 A.M.
Weather: Clear, few cirrus distant S-W
Temperature: 62F; Dew Point: 52F; Relative Humidity: 70%
Wind: ENE @ 6 kts, wind light
Sea-level pressure: 1021.9 mb; 30.18 in. Hg: rising unsteadily
Visibility: 40 miles, hazy
6-hr Max temp: 62F
6-hr Min temp: 55F
24-hr Precip: 0.00 inches
BHO SA 1155 CLR 40 219/62/52/0706/018/ FEW CI DSNT S-W HAZY
WND LGT/ 8/001 52017 10062 20055
10 A.M.
Weather: Clear, few cirrus distant SSE-WNW
Temperature: 70F; Dew Point: 51F; Relative Humidity: 51%
Wind: SE @ 5 kts, wind light and variable
Sea-level pressure: 1022.3 mb; 30.19 in. Hg: rising steadily
Visibility: 40 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 CLR 40 223/70/51/1405/019/ FEW CI DSNT SSE-WNW HAZY
WND L/V/ 8/001 52004
1 P.M.
Weather: Scattered cirrus
Temperature: 76F; Dew Point: 52F; Relative Humidity: 43%
Wind: SSW @ 6 kts, wind light
Sea-level pressure: 1021.1 mb; 30.15 in. Hg: falling steadily
Visibility: 40 miles, hazy
6-hr Max temp: 77F
6-hr Min temp: 62F
6-hr Precip: 0.00 inches
BHO SA 1755 250 SCT 40 211/76/52/2006/015/ HAZY WND LGT/
8/001 57012 10077 20062
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SUMMARY FOR FRIDAY, SEPTEMBER 11, 2026
TEMPERATURE (DEGREES F)
MAX…….77 NORMAL…..75
MIN…….59 NORMAL…..57
MEAN……68 NORMAL…..66
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+2
TOTAL DEPARTURE FOR THE MONTH (SEP)………………….+3 [+0.1 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2026 THRU JUN 2027)
TOTAL HEATING UNITS FOR YESTERDAY……………..0 DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE MONTH (SEP)………..6 DEPARTURE……..-9
TOTAL HEATING UNITS FOR THE SEASON…………….9 DEPARTURE…….-24
TOTAL HEATING UNITS LAST SEASON TO DATE……….41 DEPARTURE…….-321
COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..3 DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH (SEP)……….37 DEPARTURE……..-6
TOTAL COOLING UNITS FOR THE SEASON…………..791 DEPARTURE……+152
TOTAL COOLING UNITS LAST SEASON TO DATE………699 DEPARTURE…….+92
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)………..23 NW @ 09:16 A.M.
VECTOR #1 (1-Sec)……….23 NW @ 09:14 A.M.
VECTOR #2 (1-Sec)……….23 WNW @ 12:07 A.M.
DAVIS #1……………….22 WNW @ 09:15 A.M.
DAVIS #2 ………………20 WNW @ 12:07 A.M.
RMY #1 (Instantaneous)…..25 NW @ 09:14 A.M.
RMY #2 (Instantaneous)…..22 WNW @ 12:07 A.M.
MERLIN…………………23 NW
RICHARDS (C5C) (Inst)……24 NW @ 09:14 A.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………16 WNW @ 01:34 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..15 NW @ 03:16 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17 WNW @ 12:09 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………16 W @ 12:57 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 WNW @ 12:09 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..15 NW @ 03:15 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 WNW @ 12:09 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………15 NW @ 04:09 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..9.4 WNW [225 total miles]
VECTOR #1………………9.6
VECTOR #2……………..10.0
DAVIS #1……………….9.7 NW
DAVIS #2……………….9.1 NW
RMY #1…………………9.4 NW
RMY #2…………………9.8 NW
RICHARDS (C5C)………….9.9
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH (SEP)……..1.03 DEPARTURE…..-0.28
TOTAL PRECIPITATION FOR THE YEAR (2026)…….27.02 DEPARTURE…..-8.90
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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 The low since midnight is 55F, the daily normal low is 57F.
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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 12
HIGH 92F IN 1961
LOW 42F IN 1958,1967,1985
PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA)
PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA)
RECORDS FOR SEPTEMBER 13
HIGH 91F IN 1957
LOW 40F IN 1985
PRECIP 3.10 INCHES IN 1987
PEAK GUST 44 MPH WNW IN 1986
TODAY’S REPORT PREPARED BY: Matt Douglas
