Thursday, September 10, 2026

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

THURSDAY, SEPTEMBER 10, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0519E
SUNSET:  1803E

OVERNIGHT SHOWERS, THEN GRADUALLY BECOMING MOSTLY SUNNY THIS
MORNING….

As a warm front moved through the area last evening, a band of
rain showers accompanied it bringing only light amounts of
rainfall to Blue Hill. The total rainfall was only 0.02″! The
showers moved out by 1:30am this morning, but clouds lingered
well into this morning as a cold front approached the region.
This front pushed through dry early this morning with the only
demarcation being a wind shift from southwest to west. Clouds
gradually decreased thereafter with increasing sunshine by the
mid morning hours.

Diurnal clouds have popped up early this afternoon as well
giving us a mix of sun and clouds this afternoon.

Temperatures are on the warm side despite the passage of a cold
front as the cooler and drier air mass is lagging behind by
several hours. Readings have warmed into the low to mid 80s
this afternoon with the downsloping westerly wind. It’s been
rather humid today as well, although the air mass is very
gradually drying out this afternoon. Dew point values were in
the upper 60s this morning, but has been gradually dropping
into the lower 60s this afternoon.

Winds have been busy since late yesterday afternoon. Gusts
overnight were approaching 40mph! They have remained busy today,
but not as strong as prior to the cold frontal passage. As
mentioned, the wind gradually shifted from the southwest during
the wee hours of the morning into the west by mid morning. It’s
been gusty out of the west since. The average speed for the day
so far is around 17mph. The peak gust for the day is 38mph,
which occurred just after 2am this morning.

Visibility has been gradually improving throughout the day as
the air mass gradually changes. The view was around 30 miles
early this morning, but has improved to around 50 mile by the
1pm observation.

The maximum temperature so far today is 83F, which is 8 degrees
above the normal high of 75F. The minimum temperature since
midnight is 67F, which is 9 degrees above the normal low of 58F.

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Today’s Observations:

7 A.M.
Weather: Broken altocumulus, broken cirrus, few stratocumulus
distant all quadrants
Temperature: 70F; Dew Point: 68F; Relative Humidity: 93%
Wind: WSW @ 10G16 kts
Sea-level pressure: 1010.5 mb; 29.84 in. Hg: falling, then rising
Visibility: 30 miles, thin fog
6-hr Max temp: 71F
6-hr Min temp: 67F
24-hr Precip: 0.02 inches
BHO SA 1155 E100 BKN 250 BKN 30 105/70/68/2510G16/984/
FEW SC DSNT ALQDS THN F ALQDS/ 8/551 55001 6000/ 70002 10071 20067

10 A.M.
Weather: Broken cirrus, few cumulus all quadrants
Temperature: 79F; Dew Point: 64F; Relative Humidity: 59%
Wind: W @ 15G26 kts, peak wind W 30mph at 9:51 A.M.
Sea-level pressure: 1010.0 mb; 29.83 in. Hg: falling, then more slowly
Visibility: 40 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 E250 BKN 40 100/79/64/2815G26/983/ FEW CU ALQDS HAZY
PK WND 2826/51/ 8/201 56005

1 P.M.
Weather: Broken cumulus, broken cirrostratus, broken cirrus
Temperature: 82F; Dew Point: 63F; Relative Humidity: 52%
Wind: W @ 17G27 kts, peak wind W 33mph at 12:31 P.M.
Sea-level pressure: 1008.8 mb; 29.79 in. Hg: falling, then more slowly
Visibility: 50 miles
6-hr Max temp: 83F
6-hr Min temp: 70F
6-hr Precip: 0.00 inches
BHO SA 1755 E50 BKN 200 BKN 250 BKN 50 088/82/63/2717G27/979/
PK WND 2729/31/ 8/206 56012 10083 20070

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SUMMARY FOR WEDNESDAY, SEPTEMBER 9, 2026

TEMPERATURE (DEGREES F)
MAX…….80   NORMAL…..75
MIN…….58   NORMAL…..58
MEAN……69   NORMAL…..67

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+2
TOTAL DEPARTURE FOR THE MONTH (SEP)………………….-9 [-1.2 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……..-5
TOTAL HEATING UNITS FOR THE SEASON…………….9  DEPARTURE…….-20
TOTAL HEATING UNITS LAST SEASON TO DATE……….35  DEPARTURE…….-26

COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..4  DEPARTURE……..+1
TOTAL COOLING UNITS FOR THE MONTH (SEP)……….23  DEPARTURE…….-14
TOTAL COOLING UNITS FOR THE SEASON…………..777  DEPARTURE……+145
TOTAL COOLING UNITS LAST SEASON TO DATE………699  DEPARTURE…….+78

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)………..36 SSW  @   10:01 P.M.
VECTOR #1 (1-Sec)……….36 SSW  @   11:57 P.M.
VECTOR #2 (1-Sec)……….34 SSW  @   09:56 P.M.
DAVIS #1……………….36 S    @   10:01 P.M.
DAVIS #2 ………………39 S    @   07:56 P.M.
RMY #1 (Instantaneous)…..36 SSW  @   10:01 P.M.
RMY #2 (Instantaneous)…..36 SSW  @   09:56 P.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)……33 SSW  @   07:33 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………24 SSW  @   10:36 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..25 SSW  @   10:26 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..26 SSW  @   10:26 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………24 S    @   07:40 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 S    @   07:58 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..24 SSW  @   10:26 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..26 SSW  @   10:26 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………22 SSW  @   07:40 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….10.8 SSW [260 total miles] VECTOR #1……………..11.1
VECTOR #2……………..11.8
DAVIS #1………………10.6 SSW
DAVIS #2………………11.7 SSW
RMY #1………………..10.9 SSW
RMY #2………………..11.8 SSW
RICHARDS (C5C)…………10.8

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.02 DEPARTURE…..-0.10
TOTAL PRECIPITATION FOR THE MONTH (SEP)……..1.03 DEPARTURE…..-0.03
TOTAL PRECIPITATION FOR THE YEAR (2026)…….27.02 DEPARTURE…..-8.65

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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 The low since midnight is 67F, the daily normal low is 58F.

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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 10
HIGH 90F IN 1931,1989
LOW 41F IN 1956
PRECIP 5.60 INCHES IN 1999 (DAILY RECORD FOR SEPTEMBER)
PEAK GUST 48 MPH NW IN 1972

RECORDS FOR SEPTEMBER 11
HIGH 93F IN 1983, 2013
LOW 37F IN 1917
PRECIP 5.23 INCHES IN 1954 (HURRICANE EDNA)
PEAK GUST 101 MPH NW IN 1954 (HURRICANE EDNA)

TODAY’S REPORT PREPARED BY: Matt Douglas