Saturday, September 6, 2025

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

SATURDAY, SEPTEMBER 6, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0515E
SUNSET:  1809E

VERY EARLY MORNING FOG LIFTS, BUT WILDFIRE SMOKE RETURNS….

The hazy wildfire smoke from the western U.S. and/or central
Canada has returned to the area. Skies were nearly clear for
a brief time this morning following sunrise, however there was
barely any “sunshine” as the sun had that deep reddish hue
common when there is smoke in the atmosphere. The smoke has
tended to decrease a bit early this afternoon, but clouds have
since increased in coverage helping to filter the sun as well.

Temperatures overnight stayed on the warm side with the low
only dropping to 66F. This is 7 degrees above the normal low
for today’s date. With such a high launching pad, readings
have quickly risen into the mid 80s by early this afternoon.
Perhaps more jarring today is the dew point’s return to the
low 70s, which hasn’t happened since early August! It is quite
humid today, but thankfully there is a good breeze to keep the
air moving.

The wind has continued to be on the busy side today, mainly
out of the south and south-southwest. The speed has averaged
at around 14mph for the day so far. Frequent gusts over 20mph
have been occurring, with a peak gust so far of 35mph which
occurred around 12:40pm.

Visibility has been rather limited today, first due to fog,
and then the haziness from the smoke. The view was generally
been between 15-20 miles most of the morning, but has improved
to around 30 miles early this afternoon as the smoke continues
to decrease in density.

The maximum temperature so far today is 84F degrees, which is
7 degrees above the normal high of 77F. The minimum temperature
since midnight is 66 degrees, which is 7 degrees above the normal
low of 59F.

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Today’s Observations:

7 A.M.
Weather: Broken cirrus, few stratus fractus all quadrants,
smoke layer all quadrants and aloft
Temperature: 68F; Dew Point: 67F; Relative Humidity: 95%
Wind: SSW @ 12G18 kts
Sea-level pressure: 1016.5 mb; 30.02 in. Hg: rising, then more rapidly
Visibility: 15 miles, thin fog
6-hr Max temp: 68F
6-hr Min temp: 66F
24-hr Precip: 0.00 inches
BHO SA 1155 E250 BKN 15 165/68/67/2012G18/002/ FEW STFRA ALQDS
THN F ALQDS K LYR ALQDS AND ALF/ 8/701 53010 10068 20066

10 A.M.
Weather: Broken stratocumulus, smoke layer all quadrants
Temperature: 76F; Dew Point: 70F; Relative Humidity: 82%
Wind: SSW @ 14G22 kts
Sea-level pressure: 1016.2 mb; 30.01 in. Hg: rising, then falling
Visibility: 20 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 E10 BKN 20 162/76/70/2014G22/001/ K LYR ALQDS
HAZY/ 8/500 58003

1 P.M.
Weather: Scattered altocumulus, broken cirrus, towering cumulus
distant W-NW, few cumulus/fractus all quadrants, smoke layer all
quadrants
Temperature: 83F Dew Point: 72F; Relative Humidity: 67%
Wind: S @ 15G27 kts, peak wind S 35mph at 12:41 P.M.
Sea-level pressure: 1013.9 mb; 29.94 in. Hg: falling, then more rapidly
Visibility: 30 miles, hazy
6-hr Max temp: 84F
6-hr Min temp: 68F
6-hr Precip: 0.00 inches
BHO SA 1755 85 SCT E250 BKN 30 139/83/72/1915G27/994/
TCU DSNT W-NW FEW CU/CUFRA ALQDS K LYR ALQDS HAZY PK WND 1930/41/
8/251 58023 10083 20068

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SUMMARY FOR FRIDAY, SEPTEMBER 5, 2025

TEMPERATURE (DEGREES F)
MAX…….82   NORMAL…..77
MIN…….63   NORMAL…..59
MEAN……73   NORMAL…..68

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+5
TOTAL DEPARTURE FOR THE MONTH………………………..0 [-0.2 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……..-4
TOTAL HEATING UNITS FOR THE SEASON……………21  DEPARTURE……..-2
TOTAL HEATING UNITS LAST SEASON TO DATE……….14  DEPARTURE……..+7

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..8  DEPARTURE……..+4
TOTAL COOLING UNITS FOR THE MONTH…………….18  DEPARTURE……..-4
TOTAL COOLING UNITS FOR THE SEASON…………..690  DEPARTURE…….+72
TOTAL COOLING UNITS LAST SEASON TO DATE………713  DEPARTURE…….-23

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)………..30 S    @   03:21 P.M.
VECTOR #1 (1-Sec)……….31 SSW  @   03:24 P.M.
VECTOR #2 (1-Sec)……….31 SSW  @   03:56 P.M.
DAVIS #1……………….32 S    @   01:20 P.M.
DAVIS #2 ………………37 S    @   03:40 P.M.
RMY #1 (Instantaneous)…..33 SSW  @   03:07 P.M.
RMY #2 (Instantaneous)…..32 SSW  @   03:56 P.M.
MERLIN…………………29 SW
RICHARDS (C5C) (Inst)……30 SSW  @   03:54 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………25 SSW  @   03:04 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..21 SSW  @   03:22 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..23 SSW  @   04:53 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 S    @   03:53 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 S    @   03:41 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 SSW  @   03:08 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..24 SSW  @   04:54 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………21 SSW  @   03:22 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.7 SSW [328 total miles] VECTOR #1………………13.7
VECTOR #2………………14.8
DAVIS #1……………….13.2 S
DAVIS #2……………….15.1 SSW
RMY #1…………………13.3 SSW
RMY #2…………………14.9 S
RICHARDS (C5C)………….13.1

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH…………..0.12 DEPARTURE…..-0.46
TOTAL PRECIPITATION FOR THE YEAR (2025)…….31.45 DEPARTURE…..-3.74

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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   82/63/73/+5/0.12/…/..            30 SSW VEC1 31 SSW RMY 33

9/6 The low since midnight is 66F, 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 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)

RECORDS FOR SEPTEMBER 7
HIGH 92F IN 2007, 2015, 2023
LOW 40F IN 1888
PRECIP 2.91 INCHES IN 1891
PEAK GUST 58e MPH W IN 1941

TODAY’S REPORT PREPARED BY: Matt Douglas