Sunday, May 25, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SUNDAY, MAY 25, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0414E
SUNSET: 1909E
MOSTLY CLOUDY SKIES, BREEZY AND STILL COOL TODAY ON BLUE HILL….
Yesterday evening and during the overnight we received an additional
0.10″ of rain. We are still holding the #9 spot for the wettest May
on record. Below are the years with the highest May precipitation, as
compiled by our chief scientist, Mike Iacono.
BHO Highest May Precipitation, inches (1885-2025):
1) 10.10 in 2006
2) 9.16 in 1954
3) 9.14 in 1984
4) 8.65 in 2005
5) 8.18 in 1998
6) 7.91 in 1967
7) 7.81 in 1990
8) 7.55 in 1920
9) 7.30 in 2025 (through 7 AM 5/25)
10) 6.80 in 2002
There was a decent amount of sunshine early today before clouds overtook
the sky. For the remaining of the morning and early afternoon we were at
near overcast conditions, with some breaks in overcast. We have remained
dry though, and the lower dew points and cloudy conditions have kept the
temperatures below normal yet again.
Temperatures have remained in the mid 50’s for much of the day. The wind
and overcast conditions have prevented the temperatures from getting
close to our expected normals, but the dry air has been nice (and needed)
since we have been pretty soggy on the summit over the past couple of days.
The wind has had a pretty steady northwesterly flow for much of the day,
and has increased a bit in the last couple of hours. The average speed for
for the day so far is around 11mph. The peak gust so far for the day is
29mph, which occurred at 8:50 A.M.
Visibility has varied between 50-70 miles for much of the day. It has been
a beautiful day to take in the sights, despite the lack of sunshine.
The maximum temperature for today is 57F degrees, which is 12 degrees below
the normal high of 69F. The minimum temperature since midnight is 47F degrees,
which is 4 degrees below the normal low of 51F.
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Today’s Observations:
7 A.M.
Weather: Scattered altocumulus, few stratocumulus NE-SE
Temperature: 52F; Dew Point: 45F; Relative Humidity: 75%
Wind: NW @ 10 kts
Sea-level pressure: 1016.4 mb; 30.01 in. Hg: rising, then more
slowly
Visibility: 50 miles
6-hr Max temp: 52F
6-hr Min temp: 47F
24-hr Precip: 0.10 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 150 SCT 50 164/52/45/3110/001/ FEW SC NE-SE/ 8/550 51018
6000/ 70010 10052 20047
10 A.M.
Weather: Overcast stratocumulus, few breaks in overcast all quadrants,
few distant altocumulus/castellanus E-ESE
Temperature: 55F; Dew Point: 43F; Relative Humidity: 63%
Wind: NW @ 9G18 kts
Sea-level pressure: 1016.2 mb; 30.01 in. Hg: falling, then rising
Visibility: 70 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E50 OVC 70 162/55/43/3209G18/001/ FEW BINOVC ALQDS
FEW DSNT AC/ACC E-ESE/ 8/58/ 55002
1 P.M.
Weather: Overcast stratocumulus
Temperature: 57F Dew Point: 45F; Relative Humidity: 64%
Wind: WNW @ 10 kts
Sea-level pressure: 1016.8 mb; 30.03 in. Hg: falling, then rising
Visibility: 60 miles
6-hr Max temp: 57F
6-hr Min temp: 52F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E45 OVC 60 168/57/45/3010/003/ 8/5// 53006 10057 20052
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SUMMARY FOR SATURDAY, MAY 24, 2025
TEMPERATURE (DEGREES F)
MAX…….60 NORMAL…..69
MIN…….46 NORMAL…..51
MEAN……53 NORMAL…..60
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-7
TOTAL DEPARTURE FOR THE MONTH………………………+27 [+0.9 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….12 DEPARTURE……..+5
TOTAL HEATING UNITS FOR THE MONTH……………185 DEPARTURE…….-32
TOTAL HEATING UNITS FOR THE SEASON………….5583 DEPARTURE……-521
TOTAL HEATING UNITS LAST SEASON TO DATE……..5365 DEPARTURE……+218
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……..-4
TOTAL COOLING UNITS FOR THE SEASON……………14 DEPARTURE……..-4
TOTAL COOLING UNITS LAST SEASON TO DATE……….20 DEPARTURE……..-6
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)………..30 WNW @ 01:11 P.M.
VECTOR #1 (1-Sec)……….30 WNW @ 01:10 P.M.
VECTOR #2 (1-Sec)……….31 NW @ 04:30 P.M.
DAVIS #1……………….30 W @ 01:10 P.M.
DAVIS #2 ………………28 NW @ 01:10 P.M.
RMY #1 (Instantaneous)…..31 NW @ 04:30 P.M.
RMY #2 (Instantaneous)…..32 WNW @ 01:10 P.M.
MERLIN…………………28 NW
RICHARDS (C5C) (Inst)…..OTS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 WNW @ 01:11 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19 @ 01:11 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..22 @ 01:11 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 W @ 02:33 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………21 WNW @ 01:11 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..18 WNW @ 01:11 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..21 WNW @ 01:11 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.7 W [257 total miles]
VECTOR #1………………10.6
VECTOR #2………………11.3
DAVIS #1……………….11.1 W
DAVIS #2……………….11.1 WNW
RMY #1…………………10.3 W
RMY #2…………………11.0 W
RICHARDS (C5C)…………..OTS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.10 DEPARTURE…..-0.03
TOTAL PRECIPITATION FOR THE MONTH…………..7.30 DEPARTURE…..+4.42
TOTAL PRECIPITATION FOR THE YEAR (2025)…….21.42 DEPARTURE…..-0.24
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 The low since midnight is 47F, 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 25
HIGH 91F IN 2007
LOW 37F IN 1967
PRECIP 3.73 INS IN 1967
PEAK GUST 83 MPH NE IN 1967 (RECORD FOR MAY)
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
TODAY’S REPORT PREPARED BY: Amanda Joly
