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Friday, May 9, 2025

May 9, 2025

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA FRIDAY, MAY 9, 2025 ALL TIMES ARE…

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

FRIDAY, MAY 9, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0429E
SUNSET:  1853E

FOG, WIND, AND COOLER TEMPS MOVE INTO THE BLUE HILL REGION TODAY….

Today has been quite a change from the start of the month with
temperatures just barely reaching 51F today. After the rain moved
through yesterday evening, temperatures steadily dropped and have
continued to do so as a slow moving low pressure system moved
through the area. Our rainfall total yesterday was 0.04 inches,
still keeping us slightly above normal for the month at +0.28 inches.

We were dry throughout the morning hours until the anticipated rain
made its way here, which occurred just after noontime standard time.
Since then, the rain has been on the light side, and we have received
only 0.01 inches as of 1pm.

Temperatures have not recovered today, mostly due to the system
moving through, the blustery ENE wind, and persistent foggy conditions
that prevented any sunshine from coming through. Our high for the
day occurred at midnight and since then it has stayed rather isothermic
throughout the morning and early afternoon hours.

Wind speeds during the overnight were somewhat steady and around
8:30am started to increase. Our average speed for yesterday was only
about 7mph and today we are around 12mph so far. Winds have been
predominantly out of the ENE and we have had frequent gusts of around
25-30mph during the late morning. The peak gust for the day so far is
34mph and occurred just before 11:30am.

Thanks to the persistent fog we have been in the clouds up here all day.
This has made our visibility an abysmal 1/16th of a mile.

The maximum temperature for today is 51F degrees, which is 14 degrees
below the normal high of 65F. The minimum temperature since midnight
is 46F degrees, which is equal to the normal low.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 100ft
Temperature: 49F; Dew Point: 49F; Relative Humidity: 100%
Wind: ENE @ 8 kts
Sea-level pressure: 1018.5 mb; 30.08 in. Hg: rising, then falling
Visibility: 1/16th mile, fog
6-hr Max temp: 51F
6-hr Min temp: 49F
24-hr Precip:  0.04 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 X W1 1/16F 185/49/49/0608/008/ 8//// 50008 70004 10051 20049

10 A.M.
Weather: Sky obscured, vertical visibility 100ft
Temperature: 47F; Dew Point: 47F; Relative Humidity: 100%
Wind: ENE @ 11G22 kts, wind light and variable
Sea-level pressure: 1019.1 mb; 30.09 in. Hg: falling, then rising
Visibility: 1/16th mile, fog
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 X W1 1/16F 191/47/47/0611G22/009/ PK WND 0626/01/ 8//// 53006

1 P.M.
Weather: Sky obscured, vertical visibility 100ft, very light drizzle
Temperature: 46F Dew Point: 46F; Relative Humidity: 100%
Wind: ENE @ 10G18 kts
Sea-level pressure: 1018.1 mb; 30.06 in. Hg: falling, then rising
Visibility: 1/16th mile, fog
6-hr Max temp: 49F
6-hr Min temp: 46F
6-hr Precip:  0.01 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 X W1 1/16L-F 181/46/46/0610G18/006/ PCPN VRY LGT/ 8////
55010 6001/ 10049 20046

————————————————————–

SUMMARY FOR THURSDAY, MAY 8, 2025

TEMPERATURE (DEGREES F)
MAX…….74   NORMAL…..65
MIN…….51   NORMAL…..46
MEAN……63   NORMAL…..55

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+8
TOTAL DEPARTURE FOR THE MONTH………………………+46 [+5.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………..2  DEPARTURE……..-8
TOTAL HEATING UNITS FOR THE MONTH…………….43  DEPARTURE…….-45
TOTAL HEATING UNITS FOR THE SEASON………….5441  DEPARTURE……-534
TOTAL HEATING UNITS LAST SEASON TO DATE……..5242  DEPARTURE……+199

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH……………..4  DEPARTURE……..+1
TOTAL COOLING UNITS FOR THE SEASON…………….7  DEPARTURE……..+1
TOTAL COOLING UNITS LAST SEASON TO DATE………..2  DEPARTURE……..+5

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)………..18 ESE  @   04:49 P.M.
VECTOR #1 (1-Sec)……….18 ESE  @   04:49 P.M.
VECTOR #2 (1-Sec)……….18 NNE  @   10:58 P.M.
DAVIS #1……………….17 ESE  @   04:47 P.M.
DAVIS #2 ………………18 ESE  @   04:19 P.M.
RMY #1 (Instantaneous)…..18 ESE  @   02:13 P.M.
RMY #2 (Instantaneous)…..19 ESE  @   03:37 P.M.
MERLIN…………………21 ENE
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………13 ESE  @   04:49 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..13      @   04:49 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..14      @   11:00 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………13 NE   @   11:00 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………14 NE   @   11:00 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..13 ESE  @   02:35 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..14 NNE  @   11:00 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………7.3 ESE [175 total miles] VECTOR #1……………….7.8
VECTOR #2……………….7.9
DAVIS #1………………..7.9 ESE
DAVIS #2………………..7.8 E
RMY #1………………….7.6 NW
RMY #2………………….7.9 NW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.04 DEPARTURE…..-0.08
TOTAL PRECIPITATION FOR THE MONTH…………..1.28 DEPARTURE…..+0.28
TOTAL PRECIPITATION FOR THE YEAR (2025)…….15.40 DEPARTURE…..-4.38

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/…/..        18 ESE VEC1 18 ESE RMY 18

5/9 The low since midnight is 46F, the daily normal low is 46F.

————————————————————–

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 9
HIGH 93F IN 2000
LOW 31F IN 1947
PRECIP 2.72 INCHES IN 1954
SNOWFALL 5.0 INS IN 1977 (RECORD FOR MAY)
PEAK GUST 70e MPH NE IN 1977

RECORDS FOR MAY 10
HIGH 93F IN 1896
LOW 29F  IN 1900
PRECIP 1.85 INS IN 1998
SNOW 2.8 INS 1977 (7.8 INS TOTAL 5/9-5/10 1977)
PEAK GUST 64 MPH S IN 1990

TODAY’S REPORT PREPARED BY: Amanda Joly

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Blue Hill Observatory & Science Center · Legal

Data Use & Privacy Policy

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

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