Wednesday, August 13, 2025

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

WEDNESDAY, AUGUST 13, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0450E
SUNSET:  1848E

FOGGY CONDITIONS IN THE AM, FOLLOWED BY MORE HUMID AIR
BY AFTERNOON….

This morning we were in the clouds, as heavy fog was over
Blue Hill this morning. By 10am, the fog was still present,
though visibility was marginally better. After the fog lifted,
scattered cirrus was seen and some distant thunderstorms to
our west and north were visible. We remained dry though,
although rain would be welcome since we haven’t had any
precipitation since August 1st!

Temperatures were slow to warm today, mostly due to the fog
and overcast conditions for much of the morning. Because of
that, we just slightly missed out on a heat wave, unless we
manage 90F by this afternoon. At 86F now, it isn’t looking
very promising. The dew points have been a bit higher than
yesterday, so although the temperatures have been lower, it
has felt warmer. Dew points have been in the upper 60s to
low 70s today.

The wind has been out of the south-southwest for much of the
day, bringing warm, moist air with it. The average speed for
the day so far is around 10mph. The peak gust so far for the
day has reached 22mph, which occurred at 1:22pm.

Visibility was heavily impacted by the foggy conditions this
morning and only slightly improved after the fog lifted. We
were able to get between 15-25 miles of visibility due to
continued hazy conditions.

The maximum temperature so far today is 86F degrees, which is
5 degrees above the normal high of 81F. The minimum temperature
since midnight is 66F degrees, which is 3 degrees above the
normal low of 63F.

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Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200 ft
Temperature: 69F; Dew Point: 68F; Relative Humidity: 96%
Wind: SW @ 8 kts
Sea-level pressure: 1014.3 mb; 29.95 in. Hg: falling,
then rising
Visibility: 1/2 mile
6-hr Max temp: 69F
6-hr Min temp: 66F
24-hr Precip:  0.00 inches
BHO SA 1155 X W2 1/2F 143/69/68/2208/995/ 8//// 55000
10069 20066

10 A.M.
Weather: Overcast stratocumulus
Temperature: 76F; Dew Point: 71F Relative Humidity: 85%
Wind: SSW @ 10 kts
Sea-level pressure: 1013.5 mb; 29.93 in. Hg: falling,
then more slowly
Visibility: 15 miles, thin fog all quadrants
3-hr Precip: 0.00 inches
BHO SA 1455 E12 OVC 15 135/76/71/2110/993/ THN F ALQDS/
8/5// 56008

1 P.M.
Weather: Thin scattered cirrus, few cumulonimbus distant NNW,
few cumulus SSW-NW
Temperature: 86F Dew Point: 70F; Relative Humidity: 60%
Wind: SSW @ 10 kts
Sea-level pressure: 1011.8 mb; 29.88 in. Hg: steady,
then falling
Visibility: 25 miles, hazy
6-hr Max temp: 86F
6-hr Min temp: 69F
6-hr Precip:  0.00 inches
BHO SA 1755 250 -SCT 25 118/86/70/1910/988 FEW CB DSNT NNW
FEW CU SSW-NW HAZY/ 8/901 58017 10086 20069

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SUMMARY FOR TUESDAY, AUGUST 12, 2025

TEMPERATURE (DEGREES F)
MAX…….93   NORMAL…..81
MIN…….68   NORMAL…..63
MEAN……81   NORMAL…..72

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+9
TOTAL DEPARTURE FOR THE MONTH……………………….-9 [-0.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..0  DEPARTURE………0
TOTAL HEATING UNITS FOR THE MONTH……………..0  DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE SEASON…………….1  DEPARTURE……..-9
TOTAL HEATING UNITS LAST SEASON TO DATE………..2  DEPARTURE……..-1

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY…………….16  DEPARTURE……..+9
TOTAL COOLING UNITS FOR THE MONTH…………….84  DEPARTURE……..-8
TOTAL COOLING UNITS FOR THE SEASON…………..595  DEPARTURE……+116
TOTAL COOLING UNITS LAST SEASON TO DATE………609  DEPARTURE…….-14

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)………..21 SSW  @   05:49 P.M.
VECTOR #1 (1-Sec)……….21 SSW  @   05:49 P.M.
VECTOR #2 (1-Sec)……….21 SSW  @   05:12 P.M.
DAVIS #1……………….19 S    @   05:14 P.M.
DAVIS #2 ………………18 S    @   05:14 P.M.
RMY #1 (Instantaneous)…..21 SSW  @   05:12 P.M.
RMY #2 (Instantaneous)…..23 SSW  @   04:52 P.M.
MERLIN…………………19 SW
RICHARDS (C5C) (Inst)……19      @   04:59 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………15 SSW  @   05:14 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..15      @   05:14 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17      @   05:13 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………16 W    @   12:23 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 SSW  @   05:14 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..15 SSW  @   05:13 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 SSW  @   05:13 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………14      @   12:23 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………9.6 WSW [231 total miles] VECTOR #1……………….9.9
VECTOR #2………………10.3
DAVIS #1………………..9.9 WSW
DAVIS #2……………….10.1 WSW
RMY #1………………….9.5 WSW
RMY #2…………………10.3 WSW
RICHARDS (C5C)…………..9.7

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.13
TOTAL PRECIPITATION FOR THE MONTH…………..0.44 DEPARTURE…..-1.14
TOTAL PRECIPITATION FOR THE YEAR (2025)…….29.89 DEPARTURE…..-2.39

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PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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

8/1   71/57/64/-9/0.44/546/63            28 NE  VEC1 28 NE  RMY 27
8/2   75/54/65/-8/0.00/838/97            18 NNW VEC1 18 NNW RMY 18
8/3   83/59/71/-2/0.00/784/91            21 SSW VEC1 21 SSW RMY 21
8/4   84/61/73/0/0.00/757/88             17 W   VEC1 17 W   RMY 17
8/5   73/62/68/-5/0.00/480/56            28 NE  VEC1 27 NE  RMY 28
8/6   77/61/69/-4/0.00/248/29            17 ENE VEC1 17 ENE RMY 16
8/7   81/61/71/-2/0.00/…/..            18 ESE VEC1 18 ESE RMY 17
8/8   83/61/72/0/0.00/…/..             21 SSW VEC1 21 SSW RMY 21
8/9   83/60/72/0/0.00/…/..             22 S   VEC1 22 SSW RMY 22
8/10  89/61/75/+3/0.00/…/..            22 S   VEC1 22 S   RMY 21
8/11  94/67/81/+9/0.00/…/..            20 W   VEC1 19 W   RMY 19
8/12  93/68/81/+9/0.00/…/..            21 SSW VEC1 21 SSW RMY 21

8/13 The low since midnight is 66F, the daily normal low is 63F.

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AUGUST 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 AUGUST 13
HIGH 98F IN 1944, 2002
LOW 47F IN 1902, 1957
PRECIP 2.92 INCHES IN 1989
PEAK GUST 52 MPH SSE IN 1963

RECORDS FOR AUGUST 14
HIGH 99F IN 2002
LOW 46F IN 1964
PRECIP 3.06 INCHES IN 1919
PEAK GUST 61 MPH WNW IN 1963

TODAY’S REPORT PREPARED BY: Amanda Joly