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BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
FRIDAY, SEPTEMBER 18, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0527E
SUNSET: 1748E
WARMER TEMPERATURES CONTINUE BUT WITH DRIER AIR BY AFTERNOON….
Skies started mostly cloudy today, as rain showers in the area
moved out by day break. At the hill, we received just 0.03″ of
rain, giving us a total of 2.04″ for the month so far.
Since the system moved out to sea early this morning, we had some
light fog and clearing skies. All day has been full of sunshine
and warmer than average temperatures for another day of summer. With
the summer equinox just a couple days away, it’s a reminder that
it isn’t quite sweater season just yet!
Temperatures were once again mild during the overnight and we
were under some humid conditions to start. Temperatures are slightly
above normal, but the real story is the dew points which have been in
the upper 50’s and lower 60’s today. The good news is that the dew
point values have been trending down as the day has progressed, which
is nice since it seems like summer has had a strong grip on us over
the past couple of days.
Winds were light to start this morning, but have remained steady
but on the lighter side. Winds have mostly been out of the north-
northwest, occasionally shifting more northwest at times. The average
speed for the day so far is only around 9mph. The peak gust for the
day so far is 24mph, which occurred just before 10am this morning.
Visibility was impacted early this morning with thin fog and humid
conditions. By the mid morning, dew points started to drop and
skies began to clear, giving us around 60 miles of viewing pleasure
for the remainder of the observational period.
The maximum temperature so far today is 78F, which is 6 degrees
above the normal high of 72F. The minimum temperature since
midnight is 62F, which is 7 degrees above the normal low of 55F.
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Today’s Observations:
7 A.M.
Weather: Broken altocumulus, broken cirrus
Temperature: 64F; Dew Point: 64F; Relative Humidity: 100%
Wind: NNW @ 5 kts, wind light
Sea-level pressure: 1017.6 mb; 30.05 in. Hg: rising, then steady
Visibility: 40 miles, thin fog ENE-S
6-hr Max temp: 68F
6-hr Min temp: 62F
24-hr Precip: 0.03 inches
BHO SA 1155 E120 BKN 250 BKN 40 176/64/64/3305/005/ THN F ENE-S
WND LGT/ 8/051 51004 70003 10068 20062
10 A.M.
Weather: Scattered cumulus, scattered cirrus
Temperature: 76F; Dew Point: 63F; Relative Humidity: 64%
Wind: NNW @ 7 kts
Sea-level pressure: 1018.3 mb; 30.08 in. Hg: rising, then falling
Visibility: 60 miles
3-hr Precip: 0.00 inches
BHO SA 1455 30 SCT 250 SCT 60 183/76/64/3307/008/ 8/201 50007
1 P.M.
Weather: Scattered cumulus, scattered cirrus
Temperature: 77F; Dew Point: 58F; Relative Humidity: 51%
Wind: NNW @ 7 kts
Sea-level pressure: 1017.5 mb; 30.05 in. Hg: falling, then more slowly
Visibility: 60 miles
6-hr Max temp: 78F
6-hr Min temp: 64F
6-hr Precip: 0.00 inches
BHO SA 1755 45 SCT 250 SCT 60 175/77/58/3307/005/ 8/201 56008 10078 20064
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SUMMARY FOR THURSDAY, SEPTEMBER 17, 2026
TEMPERATURE (DEGREES F)
MAX…….82 NORMAL…..72
MIN…….63 NORMAL…..55
MEAN……73 NORMAL…..64
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+9
TOTAL DEPARTURE FOR THE MONTH (SEP)………………….+4 [0.0 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2026 THRU JUN 2027)
TOTAL HEATING UNITS FOR YESTERDAY……………..0 DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE MONTH (SEP)……….16 DEPARTURE…….-16
TOTAL HEATING UNITS FOR THE SEASON……………19 DEPARTURE…….-31
TOTAL HEATING UNITS LAST SEASON TO DATE……….46 DEPARTURE…….-27
COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..8 DEPARTURE……..+6
TOTAL COOLING UNITS FOR THE MONTH (SEP)……….45 DEPARTURE…….-13
TOTAL COOLING UNITS FOR THE SEASON…………..799 DEPARTURE……+145
TOTAL COOLING UNITS LAST SEASON TO DATE………703 DEPARTURE…….+96
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)………..25 SW @ 08:30 P.M.
VECTOR #1 (1-Sec)……….25 SW @ 08:30 P.M.
VECTOR #2 (1-Sec)……….25 SSW @ 07:56 P.M.
DAVIS #1……………….26 S @ 07:28 P.M.
DAVIS #2 ………………29 S @ 07:15 P.M.
RMY #1 (Instantaneous)…..27 SSW @ 08:13 P.M.
RMY #2 (Instantaneous)…..25 SSW @ 09:57 P.M.
MERLIN…………………23 SW
RICHARDS (C5C) (Inst)……24 SSW @ 10:06 P.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………18 SSW @ 08:06 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..18 SSW @ 08:06 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..18 SSW @ 08:06 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………17 S @ 07:28 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………19 S @ 07:16 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..18 SW @ 09:14 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..19 SSW @ 09:57 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………16 SSW @ 08:06 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..7.1 SSW [170 total miles]
VECTOR #1………………8.4
VECTOR #2………………8.8
DAVIS #1……………….7.9 SSW
DAVIS #2……………….8.0 SSW
RMY #1…………………8.3 SSW
RMY #2…………………8.7 SSW
RICHARDS (C5C)………….8.3
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.03 DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH (SEP)……..2.04 DEPARTURE…..-0.08
TOTAL PRECIPITATION FOR THE YEAR (2026)…….28.03 DEPARTURE…..-8.70
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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/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 The low since midnight is 62F, 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 18
HIGH 88F IN 1906
LOW 36F IN 1919
PRECIP 4.25 INCHES IN 1996
PEAK GUST 77e MPH WNW IN 1948
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
TODAY’S REPORT PREPARED BY: Amanda Joly
