Wednesday, September 24, 2025

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

WEDNESDAY, SEPTEMBER 24, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0534E
SUNSET:  1737E

A FEW RAIN SHOWERS THIS MORNING, OTHERWISE OVERCAST AND COOL….

It was nice to get a little bit of rain this morning, despite
the fact it was mostly on the light side. 0.12″ of rain was
measured through 7am, with an additional 0.04″ falling since
then. Otherwise it’s been cloudy all day with a cool wind off
the ocean. Also there has been plenty of fog around today as
well.

Temperatures have been held in the low to mid 60s today thanks
to the clouds and onshore flow. With the dew point also in the
same range, the air has been saturated, thus the fog.

The wind has been fairly steady out of the east. The average
speed for the day so far is around 8mph. The peak gust is
18mph so far, which occurred just after 10am this morning.

Visibility has been quite limited today with the showers and
fog. It has varied between 1/4 mile to as much as 3-4 miles at
times.

The maximum temperature so far today is 64F degrees, which is
6 degrees below the normal high of 70F. The minimum temperature
since midnight is 62F degrees, which is 9 degrees above the
normal low of 53F.

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Today’s Observations:

7 A.M.
Weather: Partially obscured, overcast nimbostratus, light rain showers
Temperature: 62F; Dew Point: 62F; Relative Humidity: 100%
Wind: ENE @ 6 kts, wind light
Sea-level pressure: 1019.9 mb; 30.12 in. Hg: rising steadily
Visibility: 1/2 mile, 2 miles SE-SW, fog
6-hr Max temp: 64F
6-hr Min temp: 62F
24-hr Precip: 0.12 inches
BHO SA 1155 -X E25 OVC 1/2RW-F 199/62/62/0706/012/ PCPN VRY LGT
RW-B53 VSBY 2 SE-SW WND LGT/ 8/62/ 52018 6012/ 70012 10064 20062

10 A.M.
Weather: Sky obscured, vertical visibility 300ft
Temperature: 63F; Dew Point: 63F; Relative Humidity: 99%
Wind: E @ 8 kts
Sea-level pressure: 1020.9 mb; 30.15 in. Hg: rising, then more slowly
Visibility: 3 miles, 1 mile NNE-NE, fog
3-hr Precip: 0.04 inches
BHO SA 1455 X W3 3F 209/63/63/0908/015/ VSBY 1 NNE-NE/ 8//// 51010
6004/

1 P.M.
Weather: Sky obscured, vertical visibility 300ft, light drizzle
Temperature: 63F Dew Point: 63F; Relative Humidity: 100%
Wind: E @ 8G15 kts
Sea-level pressure: 1020.8 mb; 30.14 in. Hg: falling, then rising
Visibility: 1.5 miles, fog
6-hr Max temp: 64F
6-hr Min temp: 62F
6-hr Precip: 0.04 inches
BHO SA 1755 X W3 11/2L-F 208/63/63/0808G15/014/ L-B48/ 8////
55001 6004/ 10064 20062

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SUMMARY FOR TUESDAY, SEPTEMBER 23, 2025

TEMPERATURE (DEGREES F)
MAX…….78   NORMAL…..70
MIN…….57   NORMAL…..53
MEAN……68   NORMAL…..62

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+6
TOTAL DEPARTURE FOR THE MONTH………………………-10 [-0.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-5
TOTAL HEATING UNITS FOR THE MONTH…………….39  DEPARTURE…….-18
TOTAL HEATING UNITS FOR THE SEASON……………59  DEPARTURE…….-16
TOTAL HEATING UNITS LAST SEASON TO DATE……….47  DEPARTURE…….+12

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..3  DEPARTURE……..+2
TOTAL COOLING UNITS FOR THE MONTH…………….41  DEPARTURE…….-27
TOTAL COOLING UNITS FOR THE SEASON…………..713  DEPARTURE…….+50
TOTAL COOLING UNITS LAST SEASON TO DATE………753  DEPARTURE…….-40

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)………..25 SW   @   01:21 P.M.
VECTOR #1 (1-Sec)……….25 SW   @   01:21 P.M.
VECTOR #2 (1-Sec)……….26 WSW  @   02:18 P.M.
DAVIS #1……………….25 SW   @   01:21 P.M.
DAVIS #2 ………………27 WSW  @   02:18 P.M.
RMY #1 (Instantaneous)…..26 WSW  @   02:18 P.M.
RMY #2 (Instantaneous)…..28 WSW  @   02:18 P.M.
MERLIN…………………24 W
RICHARDS (C5C) (Inst)……28 SW   @   01:21 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 SW   @   01:24 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..18 SW   @   01:22 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..18 SW   @   01:22 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………17 SW   @   01:22 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………19 SW   @   01:22 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..18 SW   @   01:22 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..18 SW   @   01:22 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………17 SW   @   01:22 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………9.5 SW [229 total miles] VECTOR #1……………….9.8
VECTOR #2………………10.2
DAVIS #1………………..9.6 SW
DAVIS #2……………….10.1 SW
RMY #1………………….9.7 SW
RMY #2…………………10.2 SW
RICHARDS (C5C)…………..9.5

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.12 DEPARTURE…..-0.03
TOTAL PRECIPITATION FOR THE MONTH…………..2.70 DEPARTURE…..-0.31
TOTAL PRECIPITATION FOR THE YEAR (2025)…….34.03 DEPARTURE…..-3.59

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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/+1/0.00/694/89            26 SSW VEC1 27 SSW RMY 28
9/5   82/63/73/+5/0.12/404/52            30 SSW VEC1 31 SSW RMY 33
9/6   84/64/74/+6/1.05/457/59            55 W   VEC1 55 W   RMY 57 TSTM
9/7   64/56/60/-7/0.97/000/00            16 WNW VEC1 16 NNE RMY 15
9/8   68/49/59/-8/0.00/508/66            21 NW  VEC1 21 NW  RMY 24
9/9   70/53/62/-5/0.00/697/91            22 ENE VEC1 23 E   RMY 23
9/10  65/54/60/-6/0.00/183/24            24 NE  VEC1 25 NE  RMY 25
9/11  77/51/64/-2/0.00/714/94            21 N   VEC1 17 N   RMY 18
9/12  71/56/64/-2/0.00/735/97            24 ENE VEC1 24 NNE RMY 23
9/13  76/55/66/+1/T/634/84               26 S   VEC1 26 S   RMY 25
9/14  79/57/68/+3/0.00/572/76            15 NE  VEC1 15 SW  RMY 15
9/15  72/57/65/0/0.00/689/92             20 N   VEC1 19 N   RMY 18
9/16  71/55/63/-1/0.00/403/54            20 E   VEC1 19 ESE RMY 19
9/17  71/55/63/-1/T/424/57               22 E   VEC1 22 E   RMY 21
9/18  75/61/68/+5/0.44/252/34            20 S   VEC1 20 S   RMY 20 TSTM
9/19  80/57/69/+6/0.00/715/97            24 N   VEC1 24 N   RMY 23
9/20  67/51/59/-4/0.00/…/..            20 SE  VEC1 19 SE  RMY 18
9/21  68/52/60/-2/0.00/…/..            18 ESE VEC1 19 SE  RMY 19
9/22  73/53/63/+1/0.00/…/..            20 SSW VEC1 20 SW  RMY 21
9/23  78/57/68/+6/0.00/…/..            25 SW  VEC1 25 SW  RMY 26

9/24 The low since midnight is 62F, the daily normal low is 53F.

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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 24
HIGH 87F IN 1959
LOW 33F IN 1885,1950,1963
PRECIP 1.19 INCHES IN 1955
PEAK GUST 54e MPH SW IN 1940

RECORDS FOR SEPTEMBER 25
HIGH 87F IN 1970
LOW 31F IN 1950
PRECIP 2.68 INCHES IN 1961
PEAK GUST 63 MPH SSW IN 1991

TODAY’S REPORT PREPARED BY: Matt Douglas