Saturday, May 24, 2025

Agreement required — click “Accept & Continue” below to review and accept the Data Use & Privacy Policy

Access to this content requires acceptance of our Data Use & Privacy Policy.

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

SATURDAY, MAY 24, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0415E
SUNSET: 1908E

SPOTTY SHOWERS AS LOW PRESSURE SYSTEM MOVES OUT OF THE AREA….

As if 3.74″ of rain wasn’t enough, we accumulated an additional
0.11″ inches yesterday evening. We are now 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) 7.22 in 2025 (through 1 PM 5/24)
10) 6.80 in 2002

We have remained mostly cloudy today, with a few breaks in the
overcast conditions. Showers have been scattered and light. As of
1pm today we have received 0.02 inches of rain.

Temperatures were holding steady in the low to mid 50’s for much of
the day. Dew points were also higher, mostly due to the pop-up brief
rain showers that were occurring in the area. We are still trending
with below average temperatures but are seeing (and feeling) a gradual
increase.

The wind has predominantly been out of the West today and much less
intense than yesterday. The average speed for the day so far is around
11mph. The peak gust so far for the day is 23mph, which occurred during
the overnight hours around 3:34am.

Visibility has struggled today, with the occasional rain showers and
higher dew point values. We were around 40 miles this morning and had
about 20 miles through the early afternoon hours.

The maximum temperature for today is 60F degrees, which is 9 degrees
below the normal high of 69F. The minimum temperature since midnight
is 46F degrees, which is 5 degrees below the normal low of 51F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Thinly broken cirrus, few stratocumulus N-ENE and ESE-S-WSW,
few altocumulus distant E-S-W-NW
Temperature: 50F; Dew Point: 48F; Relative Humidity: 92%
Wind: W @ 9 kts
Sea-level pressure: 1010.9 mb; 29.85 in. Hg: rising, then more
slowly
Visibility: 40 miles
6-hr Max temp: 50F
6-hr Min temp: 46F
24-hr Precip: 0.11 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 E250 -BKN 40 109/50/48/2709/985 FEW SC N-ENE AND ESE-S-WSW
FEW AC DSNT E-S-W-NW/ 8/551 70011 10050 20046

10 A.M.
Weather: Light rain, overcast stratocumulus, few breaks in overcast
NW and NE, virga ENE-ESE, precipitation very light
Temperature: 53F; Dew Point: 49F; Relative Humidity: 94%
Wind: W @ 8 kts
Sea-level pressure: 1010.5 mb; 29.84 in. Hg: rising, then falling
Visibility: 20 miles, thin fog all quadrants
3-hr Precip: 0.01 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E30 OVC 20RW- 105/53/49/2608/984/ FEW BINOVC NW AND NE
VIRGA ENE-ESE THN F ALQDS PCPN VRY LGT/ 8/5// 6001/ 58004

1 P.M.
Weather: Overcast stratocumulus, few breaks in overcast all quadrants,
few lower stratus fractus NE-ENE, virga NE and W-WNW, sun dimly visible
Temperature: 58F Dew Point: 50F; Relative Humidity: 74%
Wind: WSW @ 8 kts
Sea-level pressure: 1010.2 mb; 29.83 in. Hg: falling, then steady
Visibility: 30 miles
6-hr Max temp: 55F
6-hr Min temp: 42F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E30 OVC 30 102/58/50/2508/983/ FEW BINOVC ALQDS FEW LWR STFRA
NE-ENE VIRGA NE AND W-WNW SUN DMLY VSBL/ 8/5// 56003 6002/ 10060 20050

————————————————————–

SUMMARY FOR FRIDAY, MAY 23, 2025

TEMPERATURE (DEGREES F)
MAX…….56 NORMAL…..69
MIN…….41 NORMAL…..50
MEAN……49 NORMAL…..59

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………-10
TOTAL DEPARTURE FOR THE MONTH………………………+34 [+1.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….16 DEPARTURE……..+9
TOTAL HEATING UNITS FOR THE MONTH……………173 DEPARTURE…….-38
TOTAL HEATING UNITS FOR THE SEASON………….5571 DEPARTURE……-527
TOTAL HEATING UNITS LAST SEASON TO DATE……..5365 DEPARTURE……+206

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……..-3
TOTAL COOLING UNITS FOR THE SEASON……………14 DEPARTURE……..-3
TOTAL COOLING UNITS LAST SEASON TO DATE……….14 DEPARTURE………0

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)………..41 N @ 01:09 A.M.
VECTOR #1 (1-Sec)……….41 N @ 01:09 A.M.
VECTOR #2 (1-Sec)……….42 N @ 01:09 A.M.
DAVIS #1……………….36 NNE @ 01:09 A.M.
DAVIS #2 ………………38 NE @ 01:09 A.M.
RMY #1 (Instantaneous)…..42 N @ 01:31 A.M.
RMY #2 (Instantaneous)…..43 N @ 01:47 A.M.
MERLIN…………………M
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………25 N @ 01:09 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..25 @ 01:09 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..26 @ 01:10 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………25 N @ 01:10 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 NNE @ 01:10 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..24 N @ 01:09 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..25 N @ 01:10 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..11.0 WSW [263 total miles] VECTOR #1………………11.0
VECTOR #2………………11.3
DAVIS #1……………….11.0 WNW
DAVIS #2……………….11.0 NW
RMY #1…………………10.7 WNW
RMY #2…………………11.0 WNW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.11 DEPARTURE…..-0.02
TOTAL PRECIPITATION FOR THE MONTH…………..7.20 DEPARTURE…..+4.45
TOTAL PRECIPITATION FOR THE YEAR (2025)…….21.32 DEPARTURE…..-0.21

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

————————————————————–

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