Thursday, May 1, 2025

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

THURSDAY, MAY 1, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0439E
SUNSET:  1844E

MOSTLY SUNNY AND SEASONABLE TO START MAY….

Weather-wise, May is off to a great start. Mostly sunny skies,
light winds, and seasonable temperatures make it a great day to
enjoy the outdoors.

Cirrus clouds have stuck around all day, at times filtering the sunshine.
Aside from some altocumulus off in the distance to the south and west,
skies have remained mostly clear.

Temperatures are around where they should be for this time of year, with
a low this morning in the mid 40s and a high so far in the upper 60s. The
air remains dry, as the dew point has hovered in the low 30s for much
of the day.

Winds are very light, only averaging 6mph to this point, with direction
being variable. The peak gust took place around 3am this morning, with
a value of 23mph.

Visibility has been great today, beginning at 70 miles and falling
slightly to 60 miles by late morning likely due to pollen in the air.

The maximum temperature for today is 67F degrees, which is 4 degrees
above the normal high of 63F. The minimum temperature since midnight
is 43F degrees, which is 1 degree below the normal low of 44F.

————————————————————–

PRELIMINARY STATS FOR APRIL 2025

TEMPERATURE, Deg. F
Avg. Max. 59.6 [+3.3] Avg. Min. 38.9 [+1.0] Mean      49.3 [+2.2] 24-hour corrected mean: 49.3
Max. for month: 82F on the 19th
Min. for month: 24F on the  9th

HEATING DEGREE DAYS
Total heating units:    469 [-071] Total for the season:  5398 [-489] Total for last season: 5157

COOLING DEGREE DAYS
Total cooling units:      3 [ 000] Total for the season:     3 [ 000] Total for last season:    0

PRECIPITATION, Inches
Total: 3.41 [-1.35] Greatest in 24 hrs: 0.54 on the 11th-12th

SNOWFALL, Inches
Total: 1.7 [-1.1] Greatest in 24 hrs: 1.5 on the 11th-12th

WIND, mph
Avg. uncorrected wind speed: 12.9 mph
Avg. corrected wind speed:   13.2 mph
Prevailing wind direction:   West-Northwest [16%] Peak gust and direction:  53 NW on the 15th and 20th

SUNSHINE:
Campbell-Stokes card minutes: 12072 of a possible 23250, or 52%
Astronomical total minutes: 12531 of a possible 24131 or 52%

————————————————————–

Today’s Observations:

7 A.M.
Weather: Thin scattered cirrus, few altocumulus distant NE-S-WNW,
few cirrostratus distant SE-W
Temperature: 50F; Dew Point: 31F; Relative Humidity: 48%
Wind: SE @ 5 kts, wind light
Sea-level pressure: 1023.1 mb; 30.21 in. Hg: rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 50F
6-hr Min temp: 43F
24-hr Precip:  0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 250 -SCT 70 231/50/31/1305/021/ FEW AC DSNT NE-S-WNW
FEW CS DSNT SE-W WND LGT/ 8/055 51023 10050 20043

10 A.M.
Weather: Thin broken cirrus, few altocumulus SSW-NW-NNE
Temperature: 58F; Dew Point: 33F; Relative Humidity: 39%
Wind: SSW @ 3 kts, wind light and variable
Sea-level pressure: 1022.9 mb; 30.21 in. Hg: rising, then falling
Visibility: 60 miles
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E250 -BKN 60 229/58/33/2103/021/ FEW AC SSW-NW-NNE WND L/V/
8/051 58002

1 P.M.
Weather: Thin scattered cirrus, few altocumulus distant SE-WNW
Temperature: 67F Dew Point: 34F; Relative Humidity: 30%
Wind: SSW @ 3 kts, wind light
Sea-level pressure: 1020.8 mb; 30.14 in. Hg: falling, then more rapidly
Visibility: 60 miles
6-hr Max temp: 67F
6-hr Min temp: 50F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 250 -SCT 60 208/67/34/2103/014/ FEW AC DSNT SE-WNW WND LGT/
8/051 58021 10067 20050

————————————————————–

SUMMARY FOR WEDNESDAY, APRIL 30, 2025

TEMPERATURE (DEGREES F)
MAX…….73   NORMAL…..63
MIN…….50   NORMAL…..43
MEAN……62   NORMAL…..53

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+9
TOTAL DEPARTURE FOR THE MONTH………………………+69 [+2.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………..3  DEPARTURE……..-9
TOTAL HEATING UNITS FOR THE MONTH……………469  DEPARTURE…….-71
TOTAL HEATING UNITS FOR THE SEASON………….5398  DEPARTURE……-489
TOTAL HEATING UNITS LAST SEASON TO DATE……..5157  DEPARTURE……+241

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

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)………..36 NW   @   09:28 A.M.
VECTOR #1 (1-Sec)……….35 NW   @   09:28 A.M.
VECTOR #2 (1-Sec)……….40 NW   @   09:28 A.M.
DAVIS #1……………….35 WNW  @   09:28 A.M.
DAVIS #2 ………………35 NNW  @   09:28 A.M.
RMY #1 (Instantaneous)…..38 NW   @   09:28 A.M.
RMY #2 (Instantaneous)…..41 NW   @   09:28 A.M.
MERLIN…………………36 NW
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………26 NW   @   09:22 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..25      @   10:05 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..26      @   09:30 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………25 NW   @   09:20 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………25 WNW  @   08:22 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..25 NW   @   09:20 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..25 NW   @   10:05 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..14.8 NW [356 total miles] VECTOR #1………………14.5
VECTOR #2………………15.1
DAVIS #1……………….14.7 WNW
DAVIS #2……………….14.9 NW
RMY #1…………………14.1 NW
RMY #2…………………14.8 WNW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.14
TOTAL PRECIPITATION FOR THE MONTH…………..3.41 DEPARTURE…..-1.35
TOTAL PRECIPITATION FOR THE YEAR (2025)…….14.12 DEPARTURE…..-4.66

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE MONTH………………..1.7 DEPARTURE……-1.1
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……35.8 DEPARTURE…..-33.9

————————————————————–

PRELIMINARY CLIMATE SUMMARY FOR APRIL 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

4/1    55/32/44/+3/0.17/0.0/512/67       38 NW  VEC1 38 NW  RMY 40
4/2    42/27/35/-6/0.11/T/584/76         29 NNW VEC1 28 NNW RMY 29
4/3    62/32/47/+5/0.31/0.0/000/00       38 SW  VEC1 38 SW  RMY 39
4/4    69/47/58/+16/0.00/0.0/456/59      31 NW  VEC1 31 NW  RMY 30
4/5    47/36/42/-1/0.49/0.0/000/00       25 ESE VEC1 29 SE  RMY 25
4/6    51/37/44/+1/0.20/0.0/016/02       22 NNW VEC1 21 NNW RMY 21
4/7    45/34/40/-4/0.18/T/000/00         24 E   VEC1 23 NNE RMY 23
4/8    40/26/33/-11/0.10/0.1/196/25      51 W   VEC1 48 W   RMY 51
4/9    46/24/35/-9/0.00/0.0/755/96       36 WNW VEC1 33 NW  RMY 36
4/10   49/29/39/-6/0.01/0.0/569/72       23 SSW VEC1 23 SSW RMY 25
4/11   45/31/38/-7/0.39/1.2/024/03       25 ENE VEC1 27 ENE RMY 26
4/12   36/33/35/-11/0.46/0.4/000/00      39 ENE VEC1 40 E   RMY 42
4/13   42/35/39/-7/0.16/0.0/000/00       38 NE  VEC1 38 NE  RMY 40
4/14   67/35/51/+4/0.00/0.0/745/93       29 WNW VEC1 29 NNW RMY 28
4/15   66/44/55/+8/0.04/0.0/209/26       53 NW  VEC1 51 NW  RMY 54 TSTM
4/16   51/37/44/-3/T/0.0/484/60          44 WNW VEC1 43 WNW RMY 47
4/17   59/35/47/-1/0.00/0.0/800/99       35 WNW VEC1 34 WNW RMY 34
4/18   66/38/54/+4/0.00/0.0/617/76       41 SSW VEC1 42 SSW RMY 43
4/19   82/52/67/+18/T/0.0/383/47         40 WNW VEC1 40 W   RMY 40
4/20   67/45/56/+7/0.00/0.0/768/94       53 NW  VEC1 54 NW  RMY 56
4/21   63/37/50/0/0.00/0.0/566/69        30 SSW VEC1 28 SSW RMY 31
4/22   75/44/60/+10/0.26/0.0/452/55      30 SSW VEC1 30 SSW RMY 30
4/23   72/43/58/+8/0.00/0.0/792/96       24 NW  VEC1 23 NW  RMY 26
4/24   74/45/60/+9/0.00/0.0/786/95       31 S   VEC1 31 S   RMY 30
4/25   78/52/65/+14/T/0.0/299/36         30 SSW VEC1 30 SSW RMY 30
4/26   59/49/54/+2/0.52/0.0/000/00       42 SSW VEC1 42 SSW RMY 43
4/27   56/41/49/-3/0.01/0.0/334/40       48 NW  VEC1 48 NW  RMY 56
4/28   74/43/59/+7/0.00/0.0/821/98       28 NW  VEC1 27 NW  RMY 27
4/29   78/53/66/+13/0.00/0.0/722/86      43 SSW VEC1 43 SSW RMY 46
4/30   73/50/62/+9/0.00/0.0/641/76       36 NW  VEC1 35 NW  RMY 38

5/1 The low since midnight is 43F, the daily normal low is 44F.

————————————————————–

APRIL 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 1
HIGH 87F IN 1899
LOW 29F IN 1978
PRECIP 2.53 INCHES IN 1921
SNOWFALL TRACE IN 1905,1917,1921,1995,2016
PEAK GUST 57 MPH NW IN 1974

RECORDS FOR MAY 2
HIGH 92F IN 2001
LOW 29F IN 1903
PRECIP 1.36 INCHES IN 2006
SNOWFALL TRACE IN 1920, 1941
PEAK GUST 58 MPH S IN 1983

TODAY’S REPORT PREPARED BY: Joshua Polen