Monday, July 20, 2026

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

MONDAY, JULY 20, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0425E
SUNSET:  1915E

ANOTHER SPECTACULAR MID JULY DAY WITH DRY AIR AND SEASONABLE
TEMPERATURES…

Today has been another spectacular day with plenty of sunshine,
dry comfortable air, and temperatures that are near seasonable
levels. There was a little bit of some leftover smoke aloft early
this morning, but it was quite thin and has since moved out. Some
high thin cirrus clouds have been overhead most of the day as well
but hasn’t been enough to filter the sun. A few cumulus have also
popped up early this afternoon more or less adding a decorative
flare to the sky.

Temperatures started the day on the cool side with a low in the
mid to upper 50s! Readings have warmed nicely to the low 80s by
early this afternoon. Dew point readings have been holding in
the low to mid 50s, so the air is once again very comfortable
for mid July standards!

Winds have been gradually diminishing since last evening,
reaching light speeds by early this morning. Speeds have picked
up a bit early this afternoon as some mixing from aloft takes
place. It has gradually backed from the northwest to the southwest
as the day has progressed. The average speed for the day so far is
around 8mph. The peak gust for the day so far is 20mph, which
occurred around 12:40pm this afternoon.

Visibility has been decent today with a view of 50-60 miles all
day.

The maximum temperature so far today is 81F, which is 1 degree
below the normal high of 82F. The minimum temperature since
midnight is 58F, which is 6 degrees below the normal low of 64F.

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Today’s Observations:

7 A.M.
Weather: Broken cirrus, thin smoke aloft all quadrants
Temperature: 65F; Dew Point: 52F; Relative Humidity: 62%
Wind: NW @ 6 kts, wind light
Sea-level pressure: 1015.9 mb; 30.00 in. Hg: rising, then more slowly
Visibility: 60 miles
6-hr Max temp: 65F
6-hr Min temp: 58F
24-hr Precip: 0.00 inches
BHO SA 1155 E250 BKN 60 159/65/52/3106/000/ THN K LYR ALF ALQDS
WND LGT/ 8/001 51018 10065 20058

10 A.M.
Weather: Broken cirrus, few cumulus all quadrants
Temperature: 76F; Dew Point: 53F; Relative Humidity: 44%
Wind: WSW @ 3 kts, wind light and variable
Sea-level pressure: 1016.3 mb; 30.01 in. Hg: rising, then steady
Visibility: 50 miles
3-hr Precip: 0.00 inches
BHO SA 1455 E250 BKN 50 163/76/53/2403/001/ FEW CU ALQDS
WND L/V/ 8/201 51004

1 P.M.
Weather: Broken cirrus, few cumulus all quadrants
Temperature: 81F; Dew Point: 52F; Relative Humidity: 37%
Wind: SW @ 9 kts
Sea-level pressure: 1015.8 mb; 30.00 in. Hg: rising, then falling
Visibility: 50 miles
6-hr Max temp: 81F
6-hr Min temp: 65F
6-hr Precip: 0.00 inches
BHO SA 1755 E250 BKN 50 158/81/52/2209/000/ FEW CU ALQDS/
8/201 58005 10081 20065

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SUMMARY FOR SUNDAY, JULY 19, 2026

TEMPERATURE (DEGREES F)
MAX…….79   NORMAL…..82
MIN…….63   NORMAL…..64
MEAN……71   NORMAL…..73

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-2
TOTAL DEPARTURE FOR THE MONTH………………………+59 [+2.9 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)………203  DEPARTURE…….+56
TOTAL COOLING UNITS FOR THE SEASON…………..442  DEPARTURE……+156
TOTAL COOLING UNITS LAST SEASON TO DATE………397  DEPARTURE…….+45

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)………..43 WNW  @   09:33 A.M.*
VECTOR #1 (1-Sec)……….41 WNW  @   09:33 A.M.
VECTOR #2 (1-Sec)……….41 NW   @   09:17 A.M.
DAVIS #1……………….40 NW   @   06:30 A.M.
DAVIS #2 ………………36 NNW  @   09:17 A.M.
RMY #1 (Instantaneous)…..43 WNW  @   09:33 A.M.
RMY #2 (Instantaneous)…..41 NW   @   06:30 A.M.
MERLIN…………………41 NW
RICHARDS (C5C) (Inst)……43 WNW  @   09:33 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………29 NW   @   09:18 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..26 NW   @   09:18 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..29 NW   @   09:16 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………28 NW   @   09:18 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………27 NNW  @   09:17 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..27 NW   @   09:18 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..27 NW   @   09:16 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………26 WNW  @   09:35 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.8 NW [332 total miles] VECTOR #1………………13.5
VECTOR #2………………14.4
DAVIS #1……………….13.9 WNW
DAVIS #2……………….13.4 NW
RMY #1…………………13.3 WNW
RMY #2…………………13.9 WNW
RICHARDS (C5C)………….13.6

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…..+0.34
TOTAL PRECIPITATION FOR THE YEAR (2026)…….21.11 DEPARTURE…..-8.23

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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 The low since midnight is 58F, 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 20
HIGH 99F IN 1991
LOW 47F IN 1890
PRECIP 1.64 INS IN 1938
WIND 56e MPH SSW IN 1943

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

TODAY’S REPORT PREPARED BY: Matt Douglas