Saturday, September 27, 2025

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

SATURDAY, SEPTEMBER 27, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0537E
SUNSET:  1732E

CONTINUED WARM AND A BIT HUMID TODAY WITH PLENTY SUNSHINE….

Today has featured plenty of sunshine through some high thin
cirrus clouds. Some diurnal cumulus has also popped up during
the late morning and early afternoon hours due to strong surface
heating into a somewhat cooler air mass aloft.

Temperatures have quickly warmed today reaching the 80F degree
mark early this afternoon, which is more than 10 degrees above
the expected maximum values for this time of year. Dew point
readings remain elevated with values in the low 60s today, as
such, it still feels a bit summery out there with a humid feel
continuing.

The wind has been decreasing as the day progresses, averaging
around 9-10mph for the first several hours of the day to only
around 3-4mph over the past few hours. The wind has also become
rather variable as well. The peak gust for the day so far is
16mph, which occurred around 4:30am this morning.

Visibility has been stable at around 50 miles all day to this
point.

The maximum temperature so far today is 80F degrees, which is
12 degrees above the normal high of 68F. The minimum temperature
since midnight is 59F degrees, which is 8 degrees above the
normal low of 51F.

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Today’s Observations:

7 A.M.
Weather: Thin scattered cirrus
Temperature: 62F; Dew Point: 60F; Relative Humidity: 93%
Wind: NNW @ 8 kts
Sea-level pressure: 1016.1 mb; 30.01 in. Hg: rising, then more slowly
Visibility: 50 miles
6-hr Max temp: 63F
6-hr Min temp: 59F
24-hr Precip: 0.00 inches
BHO SA 1155 250 -SCT 50 161/62/60/3308/001/ 8/001 51023 10063 20059

10 A.M.
Weather: Thin broken cirrus, few cumulus distant SE-SW-NW
Temperature: 74F; Dew Point: 62F; Relative Humidity: 66%
Wind: NE @ 4 kts, wind light and variable
Sea-level pressure: 1017.0 mb; 30.03 in. Hg: rising, then steady
Visibility: 50 miles
3-hr Precip: 0.00 inches
BHO SA 1455 E250 -BKN 50 170/74/62/0504/003/ FEW CU DSNT SE-SW-NW
WND L/V/ 8/201 51009

1 P.M.
Weather: Broken cumulus, broken cirrus
Temperature: 78F Dew Point: 61F; Relative Humidity: 55%
Wind: S @ 4 kts, wind light and variable
Sea-level pressure: 1016.1 mb; 30.01 in. Hg: falling, then more rapidly
Visibility: 50 miles
6-hr Max temp: 80F
6-hr Min temp: 62F
6-hr Precip: 0.00 inches
BHO SA 1755 E45 BKN 250 BKN 50 161/78/61/1904/001/ WND L/V/
8/204 58009 10080 20062

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SUMMARY FOR FRIDAY, SEPTEMBER 26, 2025

TEMPERATURE (DEGREES F)
MAX…….80   NORMAL…..69
MIN…….63   NORMAL…..52
MEAN……72   NORMAL…..60

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………+12
TOTAL DEPARTURE FOR THE MONTH……………………….+9 [+0.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-6
TOTAL HEATING UNITS FOR THE MONTH…………….41  DEPARTURE…….-32
TOTAL HEATING UNITS FOR THE SEASON……………61  DEPARTURE…….-30
TOTAL HEATING UNITS LAST SEASON TO DATE……….63  DEPARTURE……..-2

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..7  DEPARTURE……..+6
TOTAL COOLING UNITS FOR THE MONTH…………….49  DEPARTURE…….-22
TOTAL COOLING UNITS FOR THE SEASON…………..721  DEPARTURE…….+54
TOTAL COOLING UNITS LAST SEASON TO DATE………753  DEPARTURE…….-32

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)………..24 NW   @   08:54 A.M.
VECTOR #1 (1-Sec)……….23 WNW  @   08:51 A.M.
VECTOR #2 (1-Sec)……….22 NW   @   08:54 A.M.
DAVIS #1……………….23 WNW  @   08:51 A.M.
DAVIS #2 ………………20 NW   @   08:54 A.M.
RMY #1 (Instantaneous)…..27 NW   @   08:54 A.M.
RMY #2 (Instantaneous)…..22 NW   @   08:54 A.M.
MERLIN…………………22 NW
RICHARDS (C5C) (Inst)……24 NW   @   08:54 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………16 W    @   08:03 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..16 W    @   04:34 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..16 NW   @   08:56 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………17 W    @   04:35 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 WSW  @   12:17 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..15 WNW  @   08:56 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..16 SW   @   12:17 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………16 WNW  @   08:56 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.1 W [242 total miles] VECTOR #1………………10.5
VECTOR #2………………10.8
DAVIS #1……………….10.8 W
DAVIS #2……………….10.1 WNW
RMY #1………………….9.9 W
RMY #2…………………10.6 W
RICHARDS (C5C)………….10.4

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.14
TOTAL PRECIPITATION FOR THE MONTH…………..4.44 DEPARTURE…..+0.99
TOTAL PRECIPITATION FOR THE YEAR (2025)…….35.77 DEPARTURE…..-2.29

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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/-4/0.00/705/96            20 SE  VEC1 19 SE  RMY 18
9/21  68/52/60/-2/0.00/593/81            18 ESE VEC1 19 SE  RMY 19
9/22  73/53/63/+1/0.00/620/85            20 SSW VEC1 20 SW  RMY 21
9/23  78/57/68/+6/0.00/305/42            25 SW  VEC1 25 SW  RMY 26
9/24  64/61/63/+2/0.19/000/00            21 E   VEC1 21 E   RMY 22
9/25  70/62/66/+5/1.67/000/00            35 SSW VEC1 35 SSW RMY 35 TSTM
9/26  80/63/72/+12/0.00/…/..           24 NW  VEC1 23 WNW RMY 27

9/27 The low since midnight is 59F, the daily normal low is 51F.

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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 27
HIGH 86F IN 2017
LOW 32F IN 1947
PRECIP 2.26 INCHES IN 1962
PEAK GUST 100 MPH SSE IN 1985 (HURRICANE GLORIA)

RECORDS FOR SEPTEMBER 28
HIGH 86F IN 2014
LOW 33F IN 1897,1947
PRECIP 2.46 INCHES IN 2004
PEAK GUST 69 MPH NE IN 1962

TODAY’S REPORT PREPARED BY: Matt Douglas