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Sunday, September 13, 2026

September 13, 2026

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA SUNDAY, SEPTEMBER 13, 2026 ALL TIMES ARE…

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

SUNDAY, SEPTEMBER 13, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0522E
SUNSET:  1757E

RAIN SHOWERS AND FOG OVERTAKE BLUE HILL AND THE REGION TODAY….

Rain showers moved into the region early this morning, though it
remained dry here until just after 8am this morning. Since then,
we have received 0.75″ of rain through 1pm EST. It is still raining
on the hill so there will be more precipitation that will be added
to the day. As of 7E this morning we were -0.41″ for the month and
-9.03″ for the year, so every drop will help us.

Temperatures have remained below normal today, mostly due to the
rain and overcast conditions. Dew points have been equal or near
equal to the air temperature, and is about 10F higher than yesterday.
So, while it is a bit cooler and raw compared to yesterday, it does
feel a bit more sticky from the increased dew points.

Winds were mostly out of the south during the overnight and early
morning hours before shifting to the southeast. Winds have been
fairly steady, with an average speed for the day so far around
13mph. The peak gust for the day so far is 26mph, which occurred
at 11:14am this morning.

Visibility was around 35 miles this morning before the rain
arrived on the summit. Since then, visibility has tanked to less
than a mile with foggy and heavy rain conditions at times.

The maximum temperature so far today is 66F, which is 8 degrees
below the normal high of 74F. The minimum temperature since
midnight is 60F, which is 3 degrees above the normal low of 57F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Broken stratocumulus, overcast cirrostratus, virga SW
and NW-NNE
Temperature: 65F; Dew Point: 63F; Relative Humidity: 95%
Wind: S @ 10 kts
Sea-level pressure: 1017.1 mb; 30.03 in. Hg: falling unsteadily
Visibility: 35 miles
6-hr Max temp: 65F
6-hr Min temp: 60F
24-hr Precip: 0.00 inches
BHO SA 1155 E45 BKN 220 OVC 35 171/65/63/1710/003/ VIRGA SW AND
NW-NNE/ 8/506 57005 10065 20060

10 A.M.
Weather: Rain showers, overcast stratus
Temperature: 65F; Dew Point: 65F; Relative Humidity: 100%
Wind: SE @ 11 kts
Sea-level pressure: 1016.0 mb; 30.00 in. Hg: falling unsteadily
Visibility: 8 miles, thin fog
3-hr Precip: 0.10 inches
BHO SA 1455 E55 OVC 8RW 160/65/65/1411/000/ THN F ALQDS/ 8/6//
57011 6010/

1 P.M.
Weather: Rain, sky obscured, vertical visibility 300ft
Temperature: 65F; Dew Point: 65F; Relative Humidity: 100%
Wind: SE @ 8 kts
Sea-level pressure: 1013.0 mb; 29.91 in. Hg: falling, then more rapidly
Visibility: 1/4 mile, fog
6-hr Max temp: 66F
6-hr Min temp: 65F
6-hr Precip: 0.75 inches
BHO SA 1755 X W3 1/4R-F 130/65/65/1309/991/ 8/6// 58030 6075/
10066 20065

————————————————————–

SUMMARY FOR SATURDAY, SEPTEMBER 12, 2026

TEMPERATURE (DEGREES F)
MAX…….77   NORMAL…..74
MIN…….55   NORMAL…..57
MEAN……66   NORMAL…..66

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………..0
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…….-12
TOTAL HEATING UNITS FOR THE SEASON…………….9  DEPARTURE…….-27
TOTAL HEATING UNITS LAST SEASON TO DATE……….42  DEPARTURE…….-33

COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..1  DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE MONTH (SEP)……….38  DEPARTURE……..-8
TOTAL COOLING UNITS FOR THE SEASON…………..792  DEPARTURE……+150
TOTAL COOLING UNITS LAST SEASON TO DATE………699  DEPARTURE…….+93

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 SSW  @   07:01 P.M.
VECTOR #1 (1-Sec)……….23 SSW  @   07:01 P.M.
VECTOR #2 (1-Sec)……….22 S    @   04:48 P.M.
DAVIS #1……………….24 S    @   07:14 P.M.
DAVIS #2 ………………26 S    @   11:17 P.M.
RMY #1 (Instantaneous)…..22 SSW  @   06:58 P.M.
RMY #2 (Instantaneous)…..22 S    @   07:08 P.M.
MERLIN…………………22 S
RICHARDS (C5C) (Inst)……21 SSW  @   06:58 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………15 SSW  @   06:49 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..15 SSW  @   06:49 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..16 S    @   06:49 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………15 S    @   06:49 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………18 S    @   07:10 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..14 S    @   10:32 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 S    @   06:49 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………14 SSW  @   06:58 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..8.3 S [198 total miles] VECTOR #1………………8.6
VECTOR #2………………9.2
DAVIS #1……………….8.3 SSE
DAVIS #2……………….9.2 S
RMY #1…………………8.5 SSE
RMY #2…………………9.2 SSE
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)……..1.03 DEPARTURE…..-0.41
TOTAL PRECIPITATION FOR THE YEAR (2026)…….27.02 DEPARTURE…..-9.03

————————————————————–

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 The low since midnight is 60F, the daily normal low is 57F.

————————————————————–

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 13
HIGH 91F IN 1957
LOW 40F IN 1985
PRECIP 3.10 INCHES IN 1987
PEAK GUST 44 MPH WNW IN 1986

RECORDS FOR SEPTEMBER 14
HIGH 90F IN 1931
LOW 34F IN 1911
PRECIP 2.90 INCHES IN 1944 (Great Atlantic Hurricane in 1944)
PEAK GUST 96e MPH E IN 1944 (Great Atlantic Hurricane in 1944)

TODAY’S REPORT PREPARED BY: Amanda Joly

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Blue Hill Observatory & Science Center · Legal

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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