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Wednesday, May 20, 2026

May 20, 2026

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA WEDNESDAY, MAY 20, 2026 ALL TIMES ARE…

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

WEDNESDAY, MAY 20, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0418E
SUNSET:  1904E

MAINLY SUNNY WITH CONTINUED WELL ABOVE NORMAL TEMPERATURES….

The upper ridge aloft is gradually being replaced with an upper
trough now over Canada sinking southward toward the region. At
the surface, high pressure remains anchored near Bermuda with
a cold front across northern New England across upstate New York
state into Pennsylvania pushing southeastward toward southern
New England.

Sunshine continues to be the theme today so far although cumulus
clouds have been increasing in coverage as we push through the
early afternoon hours.

Temperatures have reached the upper 80s today, which this time
is short of any record for the date. Dew point values have been
holding in the mid 60s through the day, so the humid feel to
the air remains.

Winds were steady through the morning, but has increased a bit
early this afternoon. It has gradually veered from the southwest
to the west-northwest as the day has progressed. The average
speed for the day so far is around 14mph. The peak gust so far
for the day is 35mph, which occurred around 11:45am this morning.

Visibility has been limited again today due to haziness, due to
the higher humidity and pollen. The view has been stuck between
30-35 miles all day.

The maximum temperature so far today is 88F degrees, which is
20 degrees above the normal high of 68F. The minimum temperature
since midnight is 65F degrees, which is 16 degrees above the
normal low of 49F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Broken cirrus, few altocumulus distant ENE-S
Temperature: 73F; Dew Point: 66F; Relative Humidity: 78%
Wind: SW @ 9 kts
Sea-level pressure: 1013.2 mb; 29.92 in. Hg: rising, then steady
Visibility: 30 miles, hazy
6-hr Max temp: 73F
6-hr Min temp: 65F
24-hr Precip: 0.25 inches
BHO SA 1155 E250 BKN 30 132/73/66/2209/992/ FEW AC DSNT ENE-S
HAZY/ 8/051 51001 70025 10073 20065

10 A.M.
Weather: Broken cirrus, few cumulus all quadrants
Temperature: 84F; Dew Point: 66F; Relative Humidity: 54%
Wind: W @ 12G22kts
Sea-level pressure: 1012.7 mb; 29.91 in. Hg: falling, then more rapidly
Visibility: 30 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 E250 BKN 30 127/84/66/2712G22/991/ FEW CU ALQDS
HAZY/ 8/101 58005

1 P.M.
Weather: Broken cumulus
Temperature: 87F; Dew Point: 67F; Relative Humidity: 51%
Wind: WNW @ 14G23 kts
Sea-level pressure: 1012.3 mb; 29.89 in. Hg: falling, then more slowly
Visibility: 35 miles, hazy
6-hr Max temp: 87F
6-hr Min temp: 73F
6-hr Precip: 0.00 inches
BHO SA 1755 E60 BKN 35 123/87/67/2914G23/989/ HAZY/
8/200 56004 10087 20073

————————————————————–

SUMMARY FOR TUESDAY, MAY 19, 2026

TEMPERATURE (DEGREES F)
MAX…….95   NORMAL…..68
MIN…….65   NORMAL…..49
MEAN……80   NORMAL…..58

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………+22
TOTAL DEPARTURE FOR THE MONTH………………………+46 [+2.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-8
TOTAL HEATING UNITS FOR THE MONTH (MAY)………155  DEPARTURE…….-28
TOTAL HEATING UNITS FOR THE SEASON………….5991  DEPARTURE…….-79
TOTAL HEATING UNITS LAST SEASON TO DATE……..5500  DEPARTURE……+491

COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY…………….15  DEPARTURE…….+14
TOTAL COOLING UNITS FOR THE MONTH (MAY)……….29  DEPARTURE…….+19
TOTAL COOLING UNITS FOR THE SEASON……………35  DEPARTURE…….+22
TOTAL COOLING UNITS LAST SEASON TO DATE……….14  DEPARTURE…….+21

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)………..47 NW   @   05:20 P.M.
VECTOR #1 (1-Sec)……….47 NW   @   05:13 P.M.
VECTOR #2 (1-Sec)……….49 WNW  @   05:13 P.M.
DAVIS #1……………….45 WNW  @   05:20 P.M.
DAVIS #2 ………………45 NW   @   05:13 P.M.
RMY #1 (Instantaneous)…..50 NW   @   05:19 P.M.
RMY #2 (Instantaneous)…..53 WNW  @   05:15 P.M.
MERLIN…………………46 NW
RICHARDS (C5C) (Inst)……47 NW   @   05:18 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………33 NW   @   05:20 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..32 NW   @   05:20 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..33 WNW  @   05:14 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………33 WNW  @   05:20 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………33 WNW  @   05:14 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..31 NW   @   05:20 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..32 WNW  @   05:15 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………32 NW   @   05:20 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.8 SW [332 total miles] VECTOR #1………………14.0
VECTOR #2………………14.6
DAVIS #1……………….13.6 SW
DAVIS #2……………….14.1 SW
RMY #1…………………13.8 SW
RMY #2…………………14.6 SW
RICHARDS (C5C)………….12.7

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.25 DEPARTURE…..+0.14
TOTAL PRECIPITATION FOR THE MONTH (MAY)……..1.29 DEPARTURE…..-0.97
TOTAL PRECIPITATION FOR THE YEAR (2026)…….14.96 DEPARTURE…..-6.08

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……0.0
TOTAL SNOWFALL FOR THE MONTH (MAY)…………..0.0 DEPARTURE……0.0
TOTAL SNOWFALL FOR THE SEASON (2025-2026)……81.6 DEPARTURE….+11.9

————————————————————–

PRELIMINARY CLIMATE SUMMARY FOR MAY 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

5/1  63/43/53/0/0.00/769/91              26 WNW VEC1 27 NNW RMY 27
5/2  58/45/52/-2/0.04/127/15             29 SSW VEC1 29 SSW RMY 28
5/3  53/41/47/-7/T/119/14                37 NW  VEC1 36 NW  RMY 39
5/4  71/41/56/+2/0.00/775/91             46 SW  VEC1 46 SW  RMY 48
5/5  78/49/64/+9/0.00/718/84             43 SSW VEC1 43 SSW RMY 45
5/6  68/54/61/+6/0.08/146/17             43 SSW VEC1 42 SSW RMY 44
5/7  65/46/56/+1/0.22/697/81             28 WNW VEC1 27 WNW RMY 28
5/8  62/40/51/-4/0.00/741/86             33 W   VEC1 33 W   RMY 33
5/9  58/43/51/-5/0.35/000/00             30 SSW VEC1 31 SSW RMY 30
5/10 72/49/61/+5/T/346/40                28 SSW VEC1 28 SSW RMY 27
5/11 62/45/54/-2/T/191/22                26 NNW VEC1 26 NNW RMY 26
5/12 63/42/53/-4/T/835/96                29 WNW VEC1 29 WNW RMY 29
5/13 65/46/56/-1/T/122/14                41 S   VEC1 40 S   RMY 44
5/14 61/48/55/-2/0.26/…/..             37 SSE VEC1 38 SE  RMY 36
5/15 56/47/52/-5/0.04/…/..             18 NE  VEC1 19 NE  RMY 20
5/16 78/47/63/+5/0.00/…/..             33 SW  VEC1 34 SSW RMY 35
5/17 86/56/71/+13/0.05/…/..            39 W   VEC1 38 W   RMY 40
5/18 84/62/73/+15/0.00/…/..            33 SSW VEC1 32 SSW RMY 33
5/19 95/65/80/+22/0.25/…/..            47 NW  VEC1 47 NW  RMY 50 TSTM

5/20 The low since midnight is 65F, the daily normal low is 49F.

————————————————————–

MAY DAILY RECORDS TO DATE

5/19 RECORD HIGH MAXIMUM TEMPERATURE OF 95F,
BEATING THE PREVIOUS RECORD OF 91F SET IN 1962

————————————————————–

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

RECORDS FOR MAY 20
HIGH 91F IN 1975,1996
LOW 37F IN 1948, 2002
PRECIP 1.97 INCHES IN 2023
PEAK GUST 57 MPH S IN 1963, WNW IN 1982

RECORDS FOR MAY 21
HIGH 92F IN 1921
LOW 35F IN 1907
PRECIP 1.61 INS IN 1954
PEAK GUST 74 MPH WSW IN 2006

TODAY’S REPORT PREPARED BY: Matt Douglas/Isabella Maser

Blue Hill Observatory & Science Center · Legal

Data Use & Privacy Policy

Please read the full Policy before accessing Observatory data · Effective January 1, 2025

Notice: By accessing, downloading, or using any Blue Hill Observatory data or services, you unconditionally accept and agree to be bound by this Policy in its entirety. If you do not agree, you may not access or use Observatory data.
Effective January 1, 2025 · Milton, Massachusetts · bluehill.org
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Effective January 1, 2025 · Blue Hill Observatory & Science Center · Milton, Massachusetts