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Wednesday, September 16, 2026

September 16, 2026

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA WEDNESDAY, SEPTEMBER 16, 2026 ALL TIMES ARE…

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BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

WEDNESDAY, SEPTEMBER 16, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0525E
SUNSET:  1752E

STILL A DECENT DAY, BUT WARMER WITH INCREASING HUMIDITY LEVELS….

As high pressure slips off to the east, a frontal system over
Great Lakes region is slowly progressing eastward toward our
region. We started the day with a deck of mid level clouds
which moved out to allow for a period of sunshine. However
more clouds, so far of mainly the high thin variety, are
starting to stream in from the west as we push through the
early afternoon period.

Temperatures are a solid 10 degrees warmer than yesterday
with readings starting the day in the mid 50s, and rebounding
to the mid to upper 70s by early this afternoon. While it
still feels nice out there, the dew point has risen from the
mid to upper 40s yesterday afternoon and evening, to around
60F by early this afternoon. Both the warmer temperature and
higher dew point are indicative of an air mass change occurring
ahead of our next slow moving cold front.

Winds were steady overnight, then went light for a spell of
time during the morning. It has started to pick up once again
by early this afternoon as it has gradually veered from a south-
southwesterly to westerly direction. The average speed for
the day so far is around 10mph. The peak gust for the day so
far is 21mph, which occurred just before 9:30am this morning.

Visibility has been gradually decreasing as the day progresses,
from around 70 miles early this morning to around 40-50 miles
by early this afternoon. As the dew point has risen, so has the
amount of haziness in the air.

The maximum temperature so far today is 78F, which is 5 degrees
above the normal high of 73F. The minimum temperature since
midnight is 53F, which is 3 degrees below the normal low of 56F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Broken altocumulus/castellanus, broken cirrus
Temperature: 58F; Dew Point: 55F; Relative Humidity: 89%
Wind: SW @ 9G16 kts
Sea-level pressure: 1028.9 mb; 30.38 in. Hg: rising unsteadily
Visibility: 70 miles
6-hr Max temp: 58F
6-hr Min temp: 54F
24-hr Precip: 0.00 inches
BHO SA 1155 E140 BKN 250 BKN 70 289/58/55/2309G16/038/ 8/081 52002
10058 20054

10 A.M.
Weather: Clear, few stratocumulus distant ESE-S, few altocumulus
distant all quadrants, few cirrus distant W-NW
Temperature: 70F; Dew Point: 58F; Relative Humidity: 66%
Wind: WSW @ 6 kts, wind light
Sea-level pressure: 1028.8 mb; 30.38 in. Hg: rising, then falling
Visibility: 50 miles
3-hr Precip: 0.00 inches
BHO SA 1455 CLR 50 288/70/58/2506/038/ FEW SC DSNT ESE-S
FEW AC DSNT ALQDS FEW CI DSNT W-NW WND LGT/ 8/551 55001

1 P.M.
Weather: Broken cirrus, few small cumulus distant ESE-SW,
few altocumulus distant S-W-NNE
Temperature: 78F; Dew Point: 60F; Relative Humidity: 54%
Wind: W @ 8G16 kts
Sea-level pressure: 1027.4 mb; 30.34 in. Hg: falling unsteadily
Visibility: 50 miles
6-hr Max temp: 78F
6-hr Min temp: 58F
6-hr Precip: 0.00 inches
BHO SA 1755 E250 BKN 50 274/78/60/2608G16/034/ FEW SML CU DSNT ESE-SW
FEW AC DSNT S-W-NNE/ 8/151 57014 10078 20058

————————————————————–

SUMMARY FOR TUESDAY, SEPTEMBER 15, 2026

TEMPERATURE (DEGREES F)
MAX…….68   NORMAL…..73
MIN…….48   NORMAL…..56
MEAN……58   NORMAL…..65

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-7
TOTAL DEPARTURE FOR THE MONTH (SEP)………………….-7 [-0.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2026 THRU JUN 2027)
TOTAL HEATING UNITS FOR YESTERDAY……………..7  DEPARTURE……..+4
TOTAL HEATING UNITS FOR THE MONTH (SEP)……….16  DEPARTURE……..-9
TOTAL HEATING UNITS FOR THE SEASON……………19  DEPARTURE…….-24
TOTAL HEATING UNITS LAST SEASON TO DATE……….42  DEPARTURE…….-23

COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE MONTH (SEP)……….38  DEPARTURE…….-15
TOTAL COOLING UNITS FOR THE SEASON…………..792  DEPARTURE……+143
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)………..18 S    @   10:00 P.M.
VECTOR #1 (1-Sec)……….18 SE   @   07:55 P.M.
VECTOR #2 (1-Sec)……….18 ESE  @   08:00 P.M.
DAVIS #1……………….18 SE   @   07:56 P.M.
DAVIS #2 ………………21 S    @   09:36 P.M.
RMY #1 (Instantaneous)…..18 SSE  @   08:31 P.M.
RMY #2 (Instantaneous)…..18 ESE  @   08:00 P.M.
MERLIN…………………17 SSE
RICHARDS (C5C) (Inst)……17 SE   @   07:55 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………14 SSW  @   11:21 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..13 SSE  @   08:54 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..14 SSW  @   11:07 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………13 S    @   11:20 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………18 S    @   09:38 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..13 SSW  @   11:19 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..15 SSW  @   11:07 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………13 SSE  @   07:57 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..7.5 N [181 total miles] VECTOR #1………………8.4
VECTOR #2………………9.0
DAVIS #1……………….8.4 E
DAVIS #2……………….8.3 E
RMY #1…………………8.4 ENE
RMY #2…………………8.9 NE
RICHARDS (C5C)………….8.7

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…..+0.18
TOTAL PRECIPITATION FOR THE YEAR (2026)…….28.00 DEPARTURE…..-8.44

————————————————————–

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 68/48/58/-7/0.00/…/..             18 S   VEC1 18 SE  RMY 18

9/16 The low since midnight is 53F, the daily normal low is 56F.

————————————————————–

SEPTEMBER DAILY RECORDS TO DATE

NONE.

————————————————————–

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)

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

RECORDS FOR SEPTEMBER 17
HIGH 87F IN 2015
LOW 38F IN 1959
PRECIP 2.73 INCHES IN 1933
PEAK GUST 60 MPH WNW IN 1999

TODAY’S REPORT PREPARED BY: Matt Douglas

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Data Use & Privacy Policy

Please read the full Policy before accessing Observatory data · Effective January 1, 2025

Notice: By accessing, downloading, or using any Blue Hill Observatory data or services, you unconditionally accept and agree to be bound by this Policy in its entirety. If you do not agree, you may not access or use Observatory data.
Effective January 1, 2025 · Milton, Massachusetts · bluehill.live
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§ 01

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Effective January 1, 2025 · Blue Hill Observatory & Science Center · Milton, Massachusetts