Tuesday, July 21, 2026

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

TUESDAY, JULY 21, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0426E
SUNSET:  1915E

LOTS OF CLOUDS TODAY WITH LIGHT RAIN SHOWERS DEVELOPING THIS
AFTERNOON….

Today started with a bit of dense fog as the summit was in the
clouds for a brief time. The clouds/fog lifted fairly quickly
allowing for some filtered sunshine for a few hours during the
mid morning period. Clouds then thicked early this afternoon
with some very light rain showers moving into the area prior to
the 1pm observation.

Temperatures are below normal today thanks to the cloud cover
and southerly flow off the South Coast. Readings only made it
to the mid 70s today (normal highs should be in the low 80s).
Dew point values are higher today than they were yesterday, as
such it does feel more humid today. Readings have generally
been in the mid 60s through the day.

Winds have mostly been out of the south today. They were lighter
during the overnight period, but started to pick up by the mid
morning hours. The average speed for the day so far is around
13mph. Gusts have on occasion exceeded 30mph, with a peak gust
for the day so far of 35mph, which occurred around 10:45am this
morning.

Visibility started the day quite limited due to the fog,
dropping as low as 1/8th of a mile for a time early this morning.
Once the fog lifted, the view improved to 40 miles for a time,
before slipping back to around 30 miles by late this morning
and early this afternoon.

The maximum temperature so far today is 76F, which is 6 degrees
below the normal high of 82F. The minimum temperature since
midnight is 60F, which is 4 degrees below the normal low of 64F.

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Today’s Observations:

7 A.M.
Weather: Overcast cirrus/cirrostratus, few thin spots in overcast
SW-NNW, few stratus fractus distant W-WNW
Temperature: 66F; Dew Point: 64F; Relative Humidity: 92%
Wind: S @ 9 kts
Sea-level pressure: 1015.3 mb; 29.98 in. Hg: falling, then more slowly
Visibility: 40 miles
6-hr Max temp: 66F
6-hr Min temp: 60F
24-hr Precip: 0.00 inches
BHO SA 1155 E200 OVC 40 153/66/64/1709/998/ FEW THN SPTS IOVC SW-NNW
FEW STFRA DSNT W-WNW SUN DMLY VSBL VSBY 30 W-WNW/ 8/607 56007
10066 20060

10 A.M.
Weather: Scattered cumulus, overcast cirrostratus
Temperature: 75F; Dew Point: 63F; Relative Humidity: 66%
Wind: S @ 13G22 kts
Sea-level pressure: 1014.9 mb; 29.97 in. Hg: rising, then falling
Visibility: 30 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 27 SCT E200 OVC 30 149/75/63/1913G22/997/
SUN DMLY VSBL HAZY/ 8/207 58004

1 P.M.
Weather: Broken altocumulus/nimbostratus, overcast cirrostratus,
few stratocumulus distant W-NNE, very light rain showers
Temperature: 74F; Dew Point: 63F; Relative Humidity: 68%
Wind: S @ 14G22 kts
Sea-level pressure: 1013.6 mb; 29.93 in. Hg: rising, then falling
Visibility: 30 miles, hazy
6-hr Max temp: 76F
6-hr Min temp: 66F
6-hr Precip: Trace
BHO SA 1755 E100 BKN 200 OVC 30RW- 136/74/63/1714G22/993/
FEW SC DSNT W-NNE SUN DMLY VSBL RW-B24 PCPN VRY LGT HAZY/
8/577 58013 6000/ 10076 20066

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SUMMARY FOR MONDAY, JULY 20, 2026

TEMPERATURE (DEGREES F)
MAX…….83   NORMAL…..82
MIN…….58   NORMAL…..64
MEAN……71   NORMAL…..73

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-2
TOTAL DEPARTURE FOR THE MONTH………………………+57 [+2.7 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 (JUL)………..2  DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE SEASON…………….2  DEPARTURE……..-3
TOTAL HEATING UNITS LAST SEASON TO DATE………..1  DEPARTURE……..+1

COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..6  DEPARTURE……..-3
TOTAL COOLING UNITS FOR THE MONTH (JUL)………209  DEPARTURE…….+53
TOTAL COOLING UNITS FOR THE SEASON…………..448  DEPARTURE……+153
TOTAL COOLING UNITS LAST SEASON TO DATE………407  DEPARTURE…….+41

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)………..24 SSW  @   06:07 P.M.*
VECTOR #1 (1-Sec)……….25 SSW  @   06:07 P.M.
VECTOR #2 (1-Sec)……….24 SSW  @   06:06 P.M.
DAVIS #1……………….24 S    @   04:30 P.M.
DAVIS #2 ………………30 S    @   06:02 P.M.
RMY #1 (Instantaneous)…..24 S    @   06:06 P.M.
RMY #2 (Instantaneous)…..25 SSW  @   06:06 P.M.
MERLIN…………………21 S
RICHARDS (C5C) (Inst)……22 SSW  @   06:07 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………16 SSW  @   05:08 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..16 S    @   04:46 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..18 S    @   04:33 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………16 S    @   04:46 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………21 S    @   04:33 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..16 S    @   04:46 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..18 S    @   04:33 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………16 SSW  @   06:07 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………9.0 WNW [216 total miles] VECTOR #1……………….9.3
VECTOR #2……………….9.9
DAVIS #1………………..9.2 SW
DAVIS #2………………..9.3 SW
RMY #1………………….9.1 WSW
RMY #2………………….9.8 WSW
RICHARDS (C5C)…………..9.4

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.11
TOTAL PRECIPITATION FOR THE MONTH (JUL)……..2.45 DEPARTURE…..+0.23
TOTAL PRECIPITATION FOR THE YEAR (2026)…….21.11 DEPARTURE…..-8.34

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PRELIMINARY CLIMATE SUMMARY FOR JULY 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

7/1  95/68/82/+11/0.00/704/77            23 WSW VEC1 23 SW  RMY 24
7/2  99/72/86/+15/0.04/822/90            40 W   VEC1 39 W   RMY 45 TSTM
7/3  98/77/88/+16/0.00/803/88            32 WNW VEC1 32 WNW RMY 34 TSTM
7/4  94/73/84/+12/0.01/765/84            29 WNW VEC1 29 WNW RMY 29
7/5  83/69/76/+4/T/355/39                20 SSE VEC1 20 SE  RMY 17
7/6  74/60/67/-5/0.05/009/01             24 E   VEC1 24 E   RMY 24
7/7  65/61/63/-9/2.11/000/00             40 ENE VEC1 39 NE  RMY 40
7/8  83/58/72/-1/0.01/780/86             26 N   VEC1 26 N   RMY 25
7/9  91/65/78/+5/0.00/834/92             29 SW  VEC1 27 SW  RMY 29
7/10 88/69/79/+6/0.00/724/80             21 NE  VEC1 21 NE  RMY 23
7/11 82/66/74/+1/0.00/795/88             20 E   VEC1 20 E   RMY 19
7/12 81/61/71/-2/0.00/884/98             18 ENE VEC1 18 ENE RMY 18
7/13 86/62/74/+1/0.00/…/..             30 SW  VEC1 30 SSW RMY 32
7/14 88/67/78/+5/0.00/…/..             32 WSW VEC1 32 WSW RMY 34
7/15 82/67/75/+2/0.00/…/..             33 WNW VEC1 33 WNW RMY 33
7/16 86/63/75/+2/0.00/…/..             33 W   VEC1 34 NNW RMY 33
7/17 83/61/72/-1/0.00/…/..             28 NW  VEC1 27 NW  RMY 28
7/18 80/64/72/-1/0.23/…/..             41 SSW VEC1 40 SSW RMY 44 TSTM
7/19 79/63/71/-2/0.00/…/..             43 WNW VEC1 41 WNW RMY 43
7/20 83/58/71/-2/0.00/…/..             24 SSW VEC1 25 SSW RMY 24

7/21 The low since midnight is 60F, the daily normal low is 64F.

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JULY DAILY RECORDS TO DATE

7/2 RECORD HIGH MAXIMUM TEMPERATURE OF 99F,
BEATING THE PREVIOUS RECORD OF 95F SET IN 1963

7/2 RECORD HIGH MINIMUM TEMPERATURE OF 72F,
THIS TIED THE RECORD WITH 1901, 1913, AND 1963

7/3 RECORD HIGH MINIMUM TEMPERATURE OF 77F,
BEATING THE PREVIOUS RECORD OF 76F SET IN 2002

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

RECORDS FOR JULY 21
HIGH 100F IN 1977 [RECORD FOR MONTH] LOW 48F IN 1890
PRECIP 2.09 INS IN 1938
PEAK GUST 60e MPH WNW IN 1977

RECORDS FOR JULY 22
HIGH 99F IN 1926, 2011
LOW 52F IN 1890
PRECIP 1.73 INS IN 1887
PEAK GUST 55 MPH IN 1983

TODAY’S REPORT PREPARED BY: Matt Douglas