Monday, May 12, 2025

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

MONDAY, MAY 12, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0426E
SUNSET:  1856E

ANOTHER DAY FULL OF SUNSHINE AND SLIGHTLY ABOVE NORMAL TEMPERATURES….

Today has featured plenty of sunshine with only some cirrus well
off to the distant south through southwest. The high pollen
count is really the only negative of the day which is reducing
visibility a bit as a haziness.

Temperatures are slightly above seasonal levels for this time of
year with readings in the upper 60s to 70F. Dew point values
remain on the low side with readings in the 30s, thus giving us
very comfortable air once again for any outdoor activities.

Winds were light and somewhat variable this morning, but have
settled out of the south-southwest and began to increase by the
late morning hours. The average speed for the day so far is around
11mph, but it’s been closer to 16-17mph for the past couple of
hours. Gusts have been exceeding 25mph since the mid to late
morning period. The peak gust so far is 32mph, which occurred
around 11:45am.

Visibility has been decent, although it has decreased a bit as
mentioned above due to the increase in pollen in the air. The view
started the day around 70 miles, but has slipped to around 50-55
miles by early this afternoon.

The maximum temperature for today is 70F degrees, which is 4 degrees
above the normal high of 66F. The minimum temperature since midnight
is 46F degrees, which is 1 degree below the normal low of 47F.

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Today’s Observations:

7 A.M.
Weather: Clear, few altocumulus distant N-E, few cirrus distant
SSE-SW
Temperature: 55F; Dew Point: 32F; Relative Humidity: 41%
Wind: S @ 6 kts, wind light
Sea-level pressure: 1029.0 mb; 30.39 in. Hg: rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 55F
6-hr Min temp: 46F
24-hr Precip:  0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 CLR 70 290/55/32/1706/039/ FEW AC DSNT N-E FEW CI DSNT
SSE-SW WND LGT/ 8/051 51008 10055 20046

10 A.M.
Weather: Clear, few cirrus distant SSE-WSW
Temperature: 64F; Dew Point: 36F; Relative Humidity: 35%
Wind: SSW @ 13G22 kts
Sea-level pressure: 1027.6 mb; 30.35 in. Hg: falling, then more rapidly
Visibility: 60 miles
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 60 276/64/36/2113G22/035/ FEW CI DSNT SSE-WSW/
8/001 58014

1 P.M.
Weather: Clear, few cirrus distant N-NNE and distant SSE-SW
Temperature: 69F Dew Point: 37F; Relative Humidity: 31%
Wind: SSW @ 16G24 kts
Sea-level pressure: 1023.6 mb; 30.23 in. Hg: falling, then more rapidly
Visibility: 50 miles
6-hr Max temp: 69F
6-hr Min temp: 55F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 CLR 50 236/69/37/2116G24/023/ FEW CI DSNT NNE-NE AND
DSNT SSE-SW/ 8/001 58040 10069 20055

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SUMMARY FOR SUNDAY, MAY 11, 2025

TEMPERATURE (DEGREES F)
MAX…….70   NORMAL…..66
MIN…….49   NORMAL…..47
MEAN……60   NORMAL…..56

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+4
TOTAL DEPARTURE FOR THE MONTH………………………+41 [+3.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………..5  DEPARTURE……..-4
TOTAL HEATING UNITS FOR THE MONTH…………….75  DEPARTURE…….-42
TOTAL HEATING UNITS FOR THE SEASON………….5473  DEPARTURE……-531
TOTAL HEATING UNITS LAST SEASON TO DATE……..5287  DEPARTURE……+186

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)………..33 NW   @   12:14 P.M.
VECTOR #1 (1-Sec)……….32 NW   @   12:13 P.M.
VECTOR #2 (1-Sec)……….32 NW   @   01:18 P.M.
DAVIS #1……………….30 WNW  @   12:13 P.M.
DAVIS #2 ………………29 NNW  @   01:18 P.M.
RMY #1 (Instantaneous)…..34 NW   @   02:10 P.M.
RMY #2 (Instantaneous)…..34 NW   @   12:54 P.M.
MERLIN…………………31 NW
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………22 NW   @   12:16 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..22      @   12:14 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..22      @   12:41 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………22 NW   @   12:14 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………21 NNW  @   12:41 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 NW   @   12:14 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..21 NW   @   12:41 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.2 NW [316 total miles] VECTOR #1………………12.9
VECTOR #2………………13.6
DAVIS #1……………….13.3 NW
DAVIS #2……………….13.4 NW
RMY #1…………………12.4 NW
RMY #2…………………13.3 WNW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH…………..2.72 DEPARTURE…..+1.38
TOTAL PRECIPITATION FOR THE YEAR (2025)…….16.84 DEPARTURE…..-3.28

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/…/..        18 ESE VEC1 18 ESE RMY 18
5/9   51/46/49/-7/1.15/0.0/…/..        33 E   VEC1 34 ENE RMY 35
5/10  62/45/54/-2/0.29/0.0/…/..        36 NW  VEC1 37 NW  RMY 41
5/11  70/49/60/+4/0.00/0.0/…/..        33 NW  VEC1 32 NW  RMY 34

5/12 The low since midnight is 46F, the daily normal low is 47F.

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MAY DAILY RECORDS TO DATE

NONE.

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

RECORDS FOR MAY 12
HIGH 88F IN 2001
LOW 29F IN 1907
PRECIP 1.49 INCHES IN 1968
SNOW TRACE IN 2019
PEAK GUST 76 MPH S IN 1974

RECORDS FOR MAY 13
HIGH 85F IN 1947
LOW 32F IN 2020
PRECIP 2.39 INCHES IN 2006
PEAK GUST 49 MPH NNW IN 1965

TODAY’S REPORT PREPARED BY: MFD