Tuesday, August 5, 2025

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

TUESDAY, AUGUST 5, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0441E
SUNSET:  1858E

WILDFIRE SMOKE PERSISTING TODAY, BUT VERY GRADUALLY THINNING….

The wildfire smoke was at its worst during the morning hours
with the visibility dropping to as low as 5-6 miles for a time.
Conditions are gradually improving as the visibility has risen
to around 20 miles by the 1pm observation. The biggest
difference today however is the much cooler temperature readings
and cloud cover passing overhead.

Temperatures were held in the 60s through late morning and
only made it to the low to mid 70s early this afternoon. This
is a refreshing change from the warm and humid conditions of
yesterday. The dew point is still on the humid side today with
readings generally in the mid 60s, however there has been a
bit of a drop to the low 60s around the time of the 1pm
observation.

The wind has been onshore all day, generally out of the northeast.
It was gusty this morning helping to bring the more refreshing
air into the area. The average speed for the day has been
around 11mph. The peak gust is 28mph, which occurred around just
after 10am this morning.

As mentioned above, the visibility was quite limited this
morning, generally under 10 miles, but has improved early this
afternoon to around 20 miles as the haziness from the smoke
begins to thin out.

The maximum temperature so far today is 73F degrees, which is
9 degrees below the normal high of 82F. The minimum temperature
since midnight is 65F degrees, which is 1 degree above the
normal low of 64F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Broken cirrus, smoke layer all quadrants
Temperature: 68F; Dew Point: 64F; Relative Humidity: 86%
Wind: NE @ 11G18 kts
Sea-level pressure: 1026.7 mb; 30.32 in. Hg: rising, then more slowly
Visibility: 7 miles, hazy
6-hr Max temp: 70F
6-hr Min temp: 65F
24-hr Precip:  0.00 inches
BHO SA 1155 E250 BKN 7 267/68/64/0511G18/032/ K LYR ALQDS HAZY/
8/002 51017 10070 20065

10 A.M.
Weather: Broken stratocumulus, broken cirrus, smoke layer all
quadrants
Temperature: 69F; Dew Point: 63F Relative Humidity: 80%
Wind: NE @ 13G21 kts
Sea-level pressure: 1028.7 mb; 30.38 in. Hg: rising, then more rapidly
Visibility: 9 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 E35 BKN 250 BKN 9 287/69/63/0513G21/038/ K LYR ALQDS
HAZY/ 8/502 53020

1 P.M.
Weather: Overcast cirrus, smoke layer all quadrants
Temperature: 73F Dew Point: 61F; Relative Humidity: 66%
Wind: ENE @ 7 kts
Sea-level pressure: 1029.2 mb; 30.39 in. Hg: rising, then falling
Visibility: 20 miles, hazy
6-hr Max temp: 73F
6-hr Min temp: 68F
6-hr Precip:  0.00 inches
BHO SA 1755 E250 OVC 20 292/73/61/0607/039/ SUN DMLY VSBL
K LYR ALQDS HAZY/ 8/002 50005 10073 20068

————————————————————–

SUMMARY FOR MONDAY, AUGUST 4, 2025

TEMPERATURE (DEGREES F)
MAX…….84   NORMAL…..82
MIN…….61   NORMAL…..64
MEAN……73   NORMAL…..73

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………..0
TOTAL DEPARTURE FOR THE MONTH………………………-19 [-5.0 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……..-1
TOTAL HEATING UNITS FOR THE SEASON…………….1  DEPARTURE……..-7
TOTAL HEATING UNITS LAST SEASON TO DATE………..0  DEPARTURE……..+1

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..8  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH…………….15  DEPARTURE…….-17
TOTAL COOLING UNITS FOR THE SEASON…………..526  DEPARTURE……+107
TOTAL COOLING UNITS LAST SEASON TO DATE………564  DEPARTURE…….-38

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)……….E17 W    @   03:27 A.M.
VECTOR #1 (1-Sec)……….17 W    @   03:27 A.M.
VECTOR #2 (1-Sec)……….17 SW   @   12:10 A.M.
DAVIS #1……………….17 W    @   03:28 A.M.
DAVIS #2 ………………16 SW   @   12:07 A.M.
RMY #1 (Instantaneous)…..17 W    @   03:27 A.M.
RMY #2 (Instantaneous)…..17 SW   @   12:10 A.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………13 SW   @   12:34 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..13      @   12:08 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..13      @   03:28 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………13 W    @   02:57 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………13 SW   @   12:32 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..13 SW   @   12:32 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..13 W    @   03:29 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………6.7 WNW [160 total miles] VECTOR #1……………….7.1
VECTOR #2……………….7.3
DAVIS #1………………..7.0 W
DAVIS #2………………..6.9 W
RMY #1………………….6.9 WSW
RMY #2………………….7.3 WSW
RICHARDS (C5C)…………..OTS

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…..-0.08
TOTAL PRECIPITATION FOR THE YEAR (2025)…….29.89 DEPARTURE…..-1.33

————————————————————–

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/…/..            28 NE  VEC1 28 NE  RMY 27
8/2   75/54/65/-8/0.00/…/..            18 NNW VEC1 18 NNW RMY 18
8/3   83/59/71/-2/0.00/…/..            21 SSW VEC1 21 SSW RMY 21
8/4   84/61/73/0/0.00/…/..             17 W   VEC1 17 W   RMY 17

8/5 The low since midnight is 65F, the daily normal low is 64F.

————————————————————–

AUGUST DAILY RECORDS TO DATE

NONE.

————————————————————–

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)

RECORDS FOR AUGUST 5
HIGH 98F IN 1955
LOW 48F IN 1929,1972
PRECIP 2.97 INCHES IN 1893
PEAK GUST 60e MPH SW 1977

RECORDS FOR AUGUST 6
HIGH 95F IN 1931, 2022
LOW 48F IN 1934
PRECIP 1.47 INCHES IN 1995
PEAK GUST 44e MPH SSW IN 1940

TODAY’S REPORT PREPARED BY: MFD/AKJ