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BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
TUESDAY, AUGUST 18, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0455E
SUNSET: 1841E
MAINLY CLOUDY SKIES TODAY AND QUITE HUMID WITH NEAR SEASONABLE
TEMPERATURES….
We started the day in the clouds (fog), but it lifted fairly
quickly this morning. Despite the lifting low level cloud deck,
a mid level cloud deck has remained giving us overcast skies for
into early this afternoon. The clouds are finally showed signs
of breaking up approaching the 1pm observation, with a mix of
sun and clouds developing thereafter.
Temperatures have so far been held in the 70s, but with a bit
more sunshine developing, readings are starting to push 80F as
of the time of this writing. The dew point has been holding in
the mid to upper 60s all day, so it has felt rather humid out
there today.
Winds were light and variable through the morning, but finally
settled out of the east-northeast by early this afternoon. While
still on the light side, the speed has become more steady between
5-10mph. The average speed for the day so far is around 5mph.
The highest wind (hard pressed to call it a gust) so far for the
day is 13mph, which occurred just after noon-time.
Visibility was quite limited early this morning due to fog, but
has been gradually improving as the day progressed. The view
early this morning was a 1/4 mile or less, becoming much better
by the 1pm observation with a view of around 40 miles.
The maximum temperature so far today is 79F, which is 1 degree
below the normal high of 80F. The minimum temperature since
midnight is 64F, which is 1 degree above the normal low of 63F.
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Today’s Observations:
7 A.M.
Weather: Broken stratus, overcast altostratus, stratus layer
occasionally drifting over summit
Temperature: 68F; Dew Point: 67F; Relative Humidity: 96%
Wind: NNE @ 2 kts, wind light and variable
Sea-level pressure: 1012.2 mb; 29.89 in. Hg: steady, then rising
Visibility: 1 mile, 1/4 mile W-N-ENE, 2 SE-S, fog
6-hr Max temp: 68F
6-hr Min temp: 64F
24-hr Precip: Trace
BHO SA 1155 E0 BKN 95 OVC 1F 122/68/67/0302/989/ ST LYR OCNLY
DRFTG OVR SMT VSBY 1/4 W-N-ENE 2 SE-S WND L/V/
8/62/ 53008 10068 20064
10 A.M.
Weather: Broken stratocumulus, overcast altostratus, few breaks in
overcast overhead-SW-NW, few lower stratus fractus all quadrants
Temperature: 74F; Dew Point: 67F; Relative Humidity: 78%
Wind: E @ 4 kts, wind light and variable
Sea-level pressure: 1013.1mb; 29.92 in. Hg: rising, then more slowly
Visibility: 30 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 E20 BKN 90 OVC 30 131/74/67/0904/992/
FEW BINOVC OVHD-SW-NW FEW LWR STFRA ALQDS HAZY WND L/V/ 8/52/ 51009
1 P.M.
Weather: Broken cumulus, broken altocumulus/altostratus,
broken cirrus
Temperature: 75F; Dew Point: 67F; Relative Humidity: 74%
Wind: ENE @ 6 kts, wind light
Sea-level pressure: 1012.6 mb; 29.90 in. Hg: falling, then rising
Visibility: 40 miles, hazy
6-hr Max temp: 79F
6-hr Min temp: 68F
6-hr Precip: 0.00 inches
BHO SA 1755 E26 BKN 60 BKN 250 BKN 40 126/75/67/0606/990/
HAZY WND LGT/ 8/271 55005 10079 20068
————————————————————–
SUMMARY FOR MONDAY, AUGUST 17, 2026
TEMPERATURE (DEGREES F)
MAX…….75 NORMAL…..80
MIN…….63 NORMAL…..63
MEAN……69 NORMAL…..72
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-3
TOTAL DEPARTURE FOR THE MONTH………………………+48 [+2.6 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2026 THRU JUN 2027)
TOTAL HEATING UNITS FOR YESTERDAY……………..0 DEPARTURE………0
TOTAL HEATING UNITS FOR THE MONTH (AUG)………..0 DEPARTURE……..-4
TOTAL HEATING UNITS FOR THE SEASON…………….2 DEPARTURE……..-9
TOTAL HEATING UNITS LAST SEASON TO DATE………..2 DEPARTURE………0
COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..4 DEPARTURE……..-3
TOTAL COOLING UNITS FOR THE MONTH (AUG)………174 DEPARTURE…….+47
TOTAL COOLING UNITS FOR THE SEASON…………..671 DEPARTURE……+157
TOTAL COOLING UNITS LAST SEASON TO DATE………645 DEPARTURE…….+26
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 *=Last of multiple occurrences
F420C (Official)………..29 S @ 05:14 A.M.
VECTOR #1 (1-Sec)……….28 S @ 05:16 A.M.
VECTOR #2 (1-Sec)……….31 S @ 05:16 A.M.
DAVIS #1……………….30 S @ 05:16 A.M.
DAVIS #2 ………………38 S @ 05:16 A.M.
RMY #1 (Instantaneous)…..32 S @ 05:16 A.M.
RMY #2 (Instantaneous)…..32 S @ 05:16 A.M.
MERLIN…………………21 S
RICHARDS (C5C) (Inst)……30 S @ 05:16 A.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 S @ 05:17 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19 S @ 05:26 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..22 S @ 05:17 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………20 S @ 05:27 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 S @ 05:17 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 S @ 05:26 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..22 S @ 05:17 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………18 S @ 05:26 A.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..8.2 S [196 total miles]
VECTOR #1………………8.5
VECTOR #2………………9.2
DAVIS #1……………….7.9 S
DAVIS #2……………….9.2 S
RMY #1…………………8.4 S
RMY #2…………………9.3 S
RICHARDS (C5C)………….8.5
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….TRACE DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH (AUG)……..0.75 DEPARTURE…..-1.46
TOTAL PRECIPITATION FOR THE YEAR (2026)…….24.85 DEPARTURE…..-8.06
————————————————————–
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 87/64/76/+3/0.00/719/83 23 SSW VEC1 24 S RMY 24
8/2 83/68/76/+3/0.01/406/47 29 S VEC1 28 S RMY 30
8/3 76/65/71/-2/0.70/121/14 44 SSW VEC1 44 SSW RMY 45 TSTM
8/4 85/61/73/0/0.00/860/100 18 W VEC1 18 W RMY 19
8/5 87/63/75/+2/0.00/694/81 21 W VEC1 21 WSW RMY 20
8/6 91/68/80/+7/0.00/539/63 21 SW VEC1 21 SW RMY 22
8/7 92/73/83/+10/T/793/93 20 SW VEC1 20 SW RMY 21
8/8 90/70/80/+8/T/723/85 29 W VEC1 29 WSW RMY 28
8/9 88/69/79/+7/0.00/814/96 28 W VEC1 27 W RMY 28
8/10 87/66/77/+5/0.00/609/72 24 W VEC1 24 W RMY 25
8/11 86/67/77/+5/0.00/792/94 26 WNW VEC1 26 WNW RMY 28
8/12 85/64/75/+3/T/781/93 18 W VEC1 18 W RMY 18
8/13 85/65/75/+3/0.01/679/81 26 WNW VEC1 25 WNW RMY 26
8/14 83/62/73/+1/0.00/710/85 21 NW VEC1 21 NNW RMY 22
8/15 81/59/70/-2/0.00/691/83 18 WNW VEC1 19 NNE RMY 19
8/16 82/57/70/-2/T/722/87 31 SW VEC1 31 SW RMY 31
8/17 75/63/69/-3/0.03/…/.. 29 S VEC1 28 S RMY 32
8/18 The low since midnight is 64F, the daily normal low is 63F.
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AUGUST DAILY RECORDS TO DATE
8/7 TIED RECORD HIGH MINIMUM TEMPERATURE OF 73F;
ALSO SET IN 2018 AND 2022
————————————————————–
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR AUGUST 18
HIGH 93F IN 2002
LOW 49F IN 1918, 1941
PRECIP 4.64 INCHES IN 1955 [DIANE]
PEAK GUST 46 MPH WNW IN 2007
RECORDS FOR AUGUST 19
HIGH 92F IN 2019
LOW 48F IN 1958
PRECIP 8.07 INCHES IN 1955 [DIANE – RECORD FOR MONTH]
PEAK GUST 78 MPH ENE IN 1991 – HURRICANE BOB
TODAY’S REPORT PREPARED BY: Matt Douglas
