Monday, May 26, 2025

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

MONDAY, MAY 26, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0413E
SUNSET:  1910E

PARTLY CLOUDY SKIES WITH PLENTY OF SUNSHINE AND COMFORTABLE AIR….

Today has been an absolutely stunning day on the summit of Blue Hill;
a great way to end the holiday weekend. We had mostly clear skies at
sunrise and then some increasing clouds by mid morning. The addition
of the sea breeze kept humidity and dew point values down which made
for a very comfortable day and perfect for outdoor frolicking.

Temperatures have recovered nicely, as the sun has helped tremendously
with daytime heating. We are finally back to our normal expected
temperatures for this time of year, which is a huge improvement over
the past week. We have had below average temperatures since May 18th!

The wind had a northwesterly flow during the overnight hours and
switched over to a north north-easterly sea breeze by the mid
morning. Winds have been on the light side for much of the day with
an average speed of only about 8 mph. Our peak gust occurred at
10:06am with a speed of around 23 mph.

Visibility has varied between 50-60 miles today, mostly thanks to
the mid level clouds, and lower humidity. Pollen counts aren’t too
high today either, which has also helped with the visibility.

The maximum temperature for today is 69F degrees, which is equal to
the normal high. The minimum temperature since midnight is 45F degrees,
which is 6 degrees below the normal low of 51F.

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Today’s Observations:

7 A.M.
Weather: Clear, few altocumulus all quadrants
Temperature: 55F; Dew Point: 48F; Relative Humidity: 77%
Wind: NNW @ 5 kts, wind light
Sea-level pressure: 1021.8 mb; 30.17 in. Hg: rising, then more
slowly
Visibility: 50 miles
6-hr Max temp: 55F
6-hr Min temp: 45F
24-hr Precip:  0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 CLR 50 218/55/48/3405/017/ FEW AC ALQDS WND LGT/ 8/050/
51019 10055 20045

10 A.M.
Weather: Broken stratocumulus
Temperature: 63F; Dew Point: 46F; Relative Humidity: 53%
Wind: NNE @ 8 kts
Sea-level pressure: 1022.3 mb; 30.19 in. Hg: rising, then steady
Visibility: 60 miles
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E50 BKN 60 223/63/46/0308/019/ 8/500 51005

1 P.M.
Weather: Scattered cumulus
Temperature: 68F Dew Point: 47F; Relative Humidity: 47%
Wind: E @ 4 kts, wind light and variable
Sea-level pressure: 1022.2 mb; 30.19 in. Hg: rising, then falling
Visibility: 70 miles
6-hr Max temp: 55F
6-hr Min temp: 69F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 55 SCT 70 222/68/56/0804/019/ WND L/V/ 8/200 58001
10069 20055

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SUMMARY FOR SUNDAY, MAY 25, 2025

TEMPERATURE (DEGREES F)
MAX…….59   NORMAL…..69
MIN…….47   NORMAL…..51
MEAN……53   NORMAL…..60

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-7
TOTAL DEPARTURE FOR THE MONTH………………………+20 [+0.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….12  DEPARTURE……..+6
TOTAL HEATING UNITS FOR THE MONTH……………197  DEPARTURE…….-27
TOTAL HEATING UNITS FOR THE SEASON………….5595  DEPARTURE……-516
TOTAL HEATING UNITS LAST SEASON TO DATE……..5365  DEPARTURE……+230

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH…………….11  DEPARTURE……..-5
TOTAL COOLING UNITS FOR THE SEASON……………14  DEPARTURE……..-5
TOTAL COOLING UNITS LAST SEASON TO DATE……….23  DEPARTURE……..-9

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)………..29 NW   @   08:50 A.M.
VECTOR #1 (1-Sec)……….29 NW   @   08:50 A.M.
VECTOR #2 (1-Sec)……….30 NW   @   08:49 A.M.
DAVIS #1……………….28 NW   @   08:47 A.M.
DAVIS #2 ………………28 W    @   08:49 A.M.
RMY #1 (Instantaneous)…..31 NW   @   08:50 A.M.
RMY #2 (Instantaneous)…..31 NW   @   08:49 A.M.
MERLIN…………………30 NW
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 NNW  @   08:51 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19      @   08:55 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..21      @   08:51 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………20 NW   @   08:55 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………20 NNW  @   08:51 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 NNW  @   08:55 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..20 NW   @   08:51 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.5 NW [251 total miles] VECTOR #1………………10.4
VECTOR #2………………11.3
DAVIS #1……………….10.7 NW
DAVIS #2……………….11.0 NW
RMY #1…………………10.1 NW
RMY #2…………………11.0 NW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.13
TOTAL PRECIPITATION FOR THE MONTH…………..7.30 DEPARTURE…..+4.29
TOTAL PRECIPITATION FOR THE YEAR (2025)…….21.42 DEPARTURE…..-0.37

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE MONTH………………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……35.8 DEPARTURE…..-33.9

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PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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   69/43/56/+3/0.00/0.0/744/88        28 S   VEC1 28 SSW RMY 28
5/2   79/47/63/+9/0.19/0.0/339/40        28 SE  VEC1 29 SE  RMY 25 TSTM
5/3   84/54/69/+15/0.15/0.0/561/66       43 SSW VEC1 42 SSW RMY 44 TSTM
5/4   77/50/64/+10/0.06/0.0/256/30       33 SW  VEC1 34 SW  RMY 32
5/5   50/46/48/-7/0.26/0.0/000/00        35 ENE VEC1 35 ENE RMY 36
5/6   61/48/55/0/0.57/0.0/000/00         26 S   VEC1 27 ENE RMY 27
5/7   72/54/63/+8/0.01/0.0/310/36        33 SSW VEC1 33 SW  RMY 35
5/8   74/51/63/+8/0.04/0.0/474/55        18 ESE VEC1 18 ESE RMY 18
5/9   51/46/49/-7/1.15/0.0/000/00        33 E   VEC1 34 ENE RMY 35
5/10  62/45/54/-2/0.29/0.0/121/14        36 NW  VEC1 37 NW  RMY 41 TSTM
5/11  70/49/60/+4/0.00/0.0/851/98        33 NW  VEC1 32 NW  RMY 34
5/12  73/46/60/+3/0.00/0.0/853/98        36 SW  VEC1 34 SW  RMY 36
5/13  70/51/61/+4/0.00/0.0/759/87        26 ESE VEC1 27 ESE RMY 26
5/14  73/48/61/+4/0.00/0.0/586/67        18 SSE VEC1 19 SSE RMY 17
5/15  72/58/65/+8/0.62/0.0/079/09        20 SSE VEC1 20 SSE RMY 19 TSTM
5/16  78/61/70/+12/0.00/0.0/404/46       23 SW  VEC1 23 SSW RMY 23
5/17  76/58/67/+9/T/0.0/264/30           30 S   VEC1 29 S   RMY 30
5/18  68/54/61/+3/T/0.0/512/58           39 W   VEC1 39 W   RMY 38
5/19  63/46/55/-3/0.00/0.0/371/42        41 NW  VEC1 42 NW  RMY 44
5/20  55/45/50/-9/T/0.0/000/00           29 NNW VEC1 29 NNW RMY 30
5/21  48/43/46/-13/0.01/0.0/009/01       28 E   VEC1 28 E   RMY 27
5/22  45/42/44/-15/3.24/0.0/000/00       46 NE  VEC1 46 NE  RMY 48 TSTM
5/23  56/41/49/-10/0.61/0.0/…/..       41 N   VEC1 41 N   RMY 42
5/24  60/46/53/-7/0.10/0.0/…/..        30 WNW VEC1 30 WNW RMY 31
5/25  59/47/53/-7/T/0.0/…/..           29 NW  VEC1 29 NW  RMY 31

5/26 The low since midnight is 45F, the daily normal low is 51F.

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MAY DAILY RECORDS TO DATE

5/16 RECORD HIGH MINIMUM TEMPERATURE OF 61F;
PREVIOUS RECORD WAS 60F SET IN 2014

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

RECORDS FOR MAY 26
HIGH 94F IN 2010
LOW 37F IN 1972,2013
PRECIP 1.73 INS IN 2003
SNOWFALL TRACE IN 1967 (Fell as ice pellets in nor’easter)
PEAK GUST 62 MPH NE IN 1967

RECORDS FOR MAY 27
HIGH 92F IN 1914
LOW 36F IN 1915
PRECIP 1.40 INS IN 1898
PEAK GUST 55 S IN 1956

TODAY’S REPORT PREPARED BY: Amanda Joly