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Monday, May 5, 2025

May 6, 2025

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA MONDAY, MAY 5, 2025 ALL TIMES ARE…

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

MONDAY, MAY 5, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0434E
SUNSET:  1849E

MUCH COOLER AND WET TODAY WITH PERIODS OF SHOWERS AND AN ONSHORE WIND….

A backdoor cold front slipped through the area between 2-3pm yesterday
afternoon. The temperature dropped quickly from the low 70s to the
mid 50s within about 1 hour’s time. The wind also shifted from the
southwest to east-northeast with the frontal passage. Off and on
rain showers with periods of drizzle in between have been the theme
since that point right through much of today. 0.26″ of rain was
measured through 7am this morning, with an additional 0.02″ being
measured up through 1pm this afternoon.

The temperature continued to drop overnight, finally bottoming out
in the upper 40s by early this morning, a value that we’ve been stuck
at since. Compared to the upper 70s yesterday and mid 80s on Saturday,
today is a bit of a shock to the system. Of course the dew point is
matching the air temperature today as the air mass is fully saturated,
and thus we’ve also been stuck in the clouds (fog) all day.

Winds have been fairly steady out of the east-northeast and northeast
today with an average speed of around 14mph for the day so far. Gusts
have been frequently exceeding 25mph since around 6am this morning.
The peak gust so far today is 35mph, which occurred just before
12:30pm.

Visibility has been quite poor as one would expect being in the
aforementioned dense fog. The view has generally been 1/8th of a mile
or less all day so far.

The maximum temperature for today is 50F degrees, which is 14 degrees
below the normal high of 64F. The minimum temperature since midnight
is 48F degrees, which is 3 degrees above the normal low of 45F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200ft, light rain showers
Temperature: 49F; Dew Point: 49F; Relative Humidity: 100%
Wind: NE @ 16G24 kts
Sea-level pressure: 1023.6 mb; 30.23 in. Hg: rising, then more rapidly
Visibility: 1/8th mile, fog
6-hr Max temp: 50F
6-hr Min temp: 49F
24-hr Precip:  0.26 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 X W2 1/8RW-F 236/49/49/0516G24/023/ RW-B01/ 8//// 53023
6020/ 70026 10050 20049

10 A.M.
Weather: Sky obscured, vertical visibility 100ft, very light drizzle
Temperature: 49F; Dew Point: 49F; Relative Humidity: 100%
Wind: ENE @ 13G23 kts, peak wind NE 31mph at 9:21 A.M.
Sea-level pressure: 1026.0 mb; 30.30 in. Hg: rising, then more slowly
Visibility: 1/16th mile, fog
3-hr Precip:  0.01 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 X W1 1/16L-F 260/49/49/0613G23/030/ PCPN VRY LGT
PK WND 0527/21/ 8//// 51024 6001/

1 P.M.
Weather: Sky obscured, vertical visibility 100ft, light drizzle
Temperature: 49F Dew Point: 49F; Relative Humidity: 100%
Wind: ENE @ 18G28 kts, peak wind ENE 35mph at 12:27 P.M.
Sea-level pressure: 1026.6 mb; 30.32 in. Hg: rising, then steady
Visibility: 1/16th mile, fog
6-hr Max temp: 50F
6-hr Min temp: 48F
6-hr Precip:  0.02 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 X W1 1/16L-F 266/49/49/0618G28/032/ RW-E48 L-B48
PK WND 0630/27/ 8//// 51006 6002/ 10050 20048

————————————————————–

SUMMARY FOR SUNDAY, MAY 4, 2025

TEMPERATURE (DEGREES F)
MAX…….77   NORMAL…..64
MIN…….50   NORMAL…..45
MEAN……64   NORMAL…..54

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………+10
TOTAL DEPARTURE FOR THE MONTH………………………+37 [+9.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………..1  DEPARTURE…….-10
TOTAL HEATING UNITS FOR THE MONTH…………….12  DEPARTURE…….-34
TOTAL HEATING UNITS FOR THE SEASON………….5410  DEPARTURE……-523
TOTAL HEATING UNITS LAST SEASON TO DATE……..5211  DEPARTURE……+199

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH……………..4  DEPARTURE……..+3
TOTAL COOLING UNITS FOR THE SEASON…………….7  DEPARTURE……..+3
TOTAL COOLING UNITS LAST SEASON TO DATE………..0  DEPARTURE……..+7

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)………..33 SW   @   01:22 P.M.
VECTOR #1 (1-Sec)……….34 SW   @   01:22 P.M.
VECTOR #2 (1-Sec)……….31 SSW  @   01:18 P.M.
DAVIS #1……………….33 WSW  @   01:22 P.M.
DAVIS #2 ………………31 S    @   01:18 P.M.
RMY #1 (Instantaneous)…..32 SW   @   01:22 P.M.
RMY #2 (Instantaneous)…..33 SSW  @   01:17 P.M.
MERLIN…………………29 S
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………23 SW   @   01:19 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..22      @   01:19 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..24      @   01:18 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………22 SSW  @   01:19 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………24 SW   @   01:23 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 SW   @   01:23 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..24 SSW  @   01:18 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.0 SSW [312 total miles] VECTOR #1………………13.1
VECTOR #2………………13.7
DAVIS #1……………….13.2 SSE
DAVIS #2……………….13.7 S
RMY #1…………………12.9 S
RMY #2…………………13.7 SSE
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.26 DEPARTURE…..+0.13
TOTAL PRECIPITATION FOR THE MONTH…………..0.61 DEPARTURE…..+0.11
TOTAL PRECIPITATION FOR THE YEAR (2025)…….14.73 DEPARTURE…..-4.55

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/…/..        28 S   VEC1 28 SSW RMY 28
5/2   79/47/63/+9/0.19/0.0/…/..        28 SE  VEC1 29 SE  RMY 25 TSTM
5/3   84/54/69/+15/0.15/0.0/…/..       43 SSW VEC1 42 SSW RMY 44 TSTM
5/4   77/50/64/+10/0.06/0.0/…/..       33 SW  VEC1 34 SW  RMY 32

5/5 The low since midnight is 48F, the daily normal low is 45F.

————————————————————–

MAY DAILY RECORDS TO DATE

NONE.

————————————————————–

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

RECORDS FOR MAY 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976

RECORDS FOR MAY 6
HIGH 90F IN 1930
LOW 29F IN 1891
PRECIP 1.04 INCHES IN 1890
SNOWFALL TRACE IN 1917, 1952, 1996
PEAK GUST 65 MPH SSE IN 1989

TODAY’S REPORT PREPARED BY: MFD

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Effective January 1, 2025 · Milton, Massachusetts · bluehill.org
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