Friday, September 5, 2025

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

FRIDAY, SEPTEMBER 5, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0514E
SUNSET:  1811E

EARLY MORNING RAIN LEAVES BEHIND HUMID CONDITIONS, BREEZY
SOUTHERLY WIND….

We received our first precipitation for the month of September
during the early morning hours today, with a total of 0.12″ of
rain. While not a lot, anything helps, as we are sitting at
around -3.62 inches in deficit for the year.

The skies immediately after the rain had featured some fog and
a mix of altocumulus and cirrus, and by mid morning we had overcast
stratocumulus. By the afternoon we finally had some clearing, with
broken cumulus clouds throughout the sky.

Temperatures overnight only dropped to 62F, with a low of 64F as
of midnight. After the passing early morning rain and the added
sunshine, we were experiencing quite a different feel, as dew
points also have increased unto the upper 60s. Temperatures
themselves have also increased only a few degrees higher than
yesterday, however, the dew point increase is what has made it
feel so much warmer today. The southerly wind bringing warmer and
more moist air has also added to the ‘stickiness factor’.

The wind picked up yesterday late afternoon and has continued
to be a steady southerly to south-southwesterly flow for much of
the day. The average speed has been around 12mph for the day
so far. The peak gust for the day so far is around 28mph, which
occurred during the overnight hours, at 12:22am.

Visibility has improved as the lingering clouds moved out of
the region. We fluctuated from about 12 miles of visibility in
the early morning to about 30 miles by the early afternoon.

The maximum temperature so far today is 81F degrees, which is
4 degrees above the normal high of 77F. The minimum temperature
since midnight is 62 degrees, which is 3 degrees above the normal
low of 59F.

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Today’s Observations:

7 A.M.
Weather: Broken stratus, broken altocumulus, broken cirrus,
sun dimly visible
Temperature: 65F; Dew Point: 65F; Relative Humidity: 100%
Wind: S @ 8 kts
Sea-level pressure: 1014.4 mb; 29.96 in. Hg: rising unsteadily
Visibility: 12 miles, fog all quadrants
6-hr Max temp: 65F
6-hr Min temp: 62F
24-hr Precip: 0.12 inches
BHO SA 1155 E6 BKN 180 BKN 250 BKN 12 144/65/65/1808/996/
THN F ALQDS SUN DMLY VSBL/ 8/651 52005 6012/ 70012 10065 20062

10 A.M.
Weather: Overcast stratocumulus
Temperature: 70F; Dew Point: 68F; Relative Humidity: 100%
Wind: SSW @ 10 kts
Sea-level pressure: 1014.9 mb; 29.97 in. Hg: falling, then
steady
Visibility: 30 miles
3-hr Precip: 0.00 inches
BHO SA 1455 E30 OVC 30 150/70/68/1910/997/ 8/5// 51006

1 P.M.
Weather: Broken cumulus
Temperature: 80F Dew Point: 65F; Relative Humidity: 60%
Wind: SSW @ 12 kts
Sea-level pressure: 1013.7 mb; 29.93 in. Hg: steady, then
falling
Visibility: 30 miles
6-hr Max temp: 81F
6-hr Min temp: 65F
6-hr Precip: 0.00 inches
BHO SA 1755 E35 BKN 30 137/80/65/2012/993/ 8/200 58013
10081 20065

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SUMMARY FOR THURSDAY, SEPTEMBER 4, 2025

TEMPERATURE (DEGREES F)
MAX…….81   NORMAL…..77
MIN…….56   NORMAL…..59
MEAN……69   NORMAL…..68

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+1
TOTAL DEPARTURE FOR THE MONTH……………………….-5 [-1.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-1
TOTAL HEATING UNITS FOR THE MONTH……………..1  DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE SEASON……………21  DEPARTURE……..-1
TOTAL HEATING UNITS LAST SEASON TO DATE……….14  DEPARTURE……..+7

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..4  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH…………….10  DEPARTURE……..-8
TOTAL COOLING UNITS FOR THE SEASON…………..682  DEPARTURE…….+68
TOTAL COOLING UNITS LAST SEASON TO DATE………710  DEPARTURE…….-28

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

F420C (Official)………..26 SSW  @   04:43 P.M.
VECTOR #1 (1-Sec)……….27 SSW  @   04:43 P.M.
VECTOR #2 (1-Sec)……….29 SSW  @   04:48 P.M.
DAVIS #1……………….27 S    @   03:34 P.M.
DAVIS #2 ………………37 S    @   04:48 P.M.
RMY #1 (Instantaneous)…..28 SSW  @   07:19 P.M.
RMY #2 (Instantaneous)…..30 SSW  @   04:48 P.M.
MERLIN…………………25 SSW
RICHARDS (C5C) (Inst)……26 SSW  @   07:19 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 S    @   04:38 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19 SSW  @   03:10 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..20 S    @   04:38 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 S    @   04:38 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………23 S    @   04:56 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 SSW  @   03:10 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..20 S    @   04:38 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………18 SSW  @   03:10 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.2 S [245 total miles] VECTOR #1………………10.5
VECTOR #2………………11.1
DAVIS #1……………….10.0 SSW
DAVIS #2……………….11.4 SSW
RMY #1…………………10.1 SSW
RMY #2…………………11.1 SSW
RICHARDS (C5C)………….10.1

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.12 DEPARTURE……0.00
TOTAL PRECIPITATION FOR THE MONTH…………..0.12 DEPARTURE…..-0.34
TOTAL PRECIPITATION FOR THE YEAR (2025)…….31.45 DEPARTURE…..-3.62

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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   73/55/64/-5/0.00/221/28            23 NE  VEC1 23 ENE RMY 23
9/2   77/58/68/-1/0.00/714/91            18 ESE VEC1 19 ESE RMY 18
9/3   78/57/68/0/0.00/719/92             21 SSW VEC1 21 SSW RMY 21
9/4   81/56/69/+1/0.00/…/..            26 SSW VEC1 27 SSW RMY 28

9/5 The low since midnight is 62F, the daily normal low is 59F.

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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 5
HIGH 90F IN 1971
LOW 45F IN 1906
PRECIP 1.37 INCHES IN 1907
PEAK GUST 46 MPH NW IN 1994

RECORDS FOR SEPTEMBER 6
HIGH 92F IN 1900, 2018
LOW 39F IN 1888
PRECIP 3.19 INCHES IN 1890
PEAK GUST 78e MPH SE IN 1979 (TROPICAL STORM DAVID)

TODAY’S REPORT PREPARED BY: Amanda Joly