Monday, June 2, 2025

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

MONDAY, JUNE 2, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0409E
SUNSET:  1916E

MUCH LESS WINDY, BUT STILL ON THE COOL SIDE WITH INCREASING CLOUDS….

Today has featured sunshine that has become less abundant as the
day has progressed. Clear skies early this morning have been
gradually filling in with diurnal cumulus clouds as an anomalously
cold (for this time of year) pool of air aloft remains over the area.
This cold pool is the result of a slow moving upper level low that
brought the wet weather over the weekend. Wildfire smoke from the
massive fires across central Canada has also reached the region,
and the smoke can be observed aloft in various directions today.

Temperatures are a bit milder than yesterday, but definitely still
on the cool side for early June. Readings started the day in the
upper 40s, and have recovered to the mid to upper 60s by early this
afternoon. Highs should be in the low 70s at this time of year.
Dew point values, which managed to dip into the upper 30s for a time
late yesterday afternoon and evening, have been slowly creeping up
today. Despite that, it’s still very pleasant for this time of year
as they remain in the 40s.

We have again today had a predominantly westerly flow, but the wind
speeds have been much less busy than yesterday. They have been
averaging at around 11mph for the day so far. While it has been a
bit gusty, it certainly hasn’t been anything like yesterday. The
peak gust so far for today is 25mph, which occurred just after 11am
this morning.

Visibility has been excellent today, holding at around 70 miles all
day!

The maximum temperature for today is 69F degrees, which is 2 degrees
below the normal high of 71F. The minimum temperature since midnight
is 48F degrees, which is 5 degrees below the normal low of 53F.

May ending up being a rather wet month (with a month’s worth of rain
falling in the 22nd-23rd nor’easter). We finished the month with a
total rainfall of 7.62 inches, making it the 8th 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) 7.62 in 2025
9) 7.55 in 1920
10) 6.80 in 2002

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PRELIMINARY STATS FOR MAY 2025

TEMPERATURE, Deg. F
Avg. Max. 67.0 [+0.2] Avg. Min. 49.3 [+1.1] Mean      58.2 [+0.7] 24-hour corrected mean: 57.4
Max. for month: 84F on the  3rd
Min. for month: 41F on the 23rd

HEATING DEGREE DAYS
Total heating units:    217 [-041] Total for the season:  5615 [-530] Total for last season: 5379

COOLING DEGREE DAYS
Total cooling units:     14 [-011] Total for the season:    17 [-011] Total for last season:   37

PRECIPITATION, Inches
Total: 7.62 [+3.80] Greatest in 24 hrs: 3.73 on the 22nd-23rd

SNOWFALL, Inches
Total: 0.0 [ 0.0] Greatest in 24 hrs: N/A

WIND, mph
Avg. uncorrected wind speed: 11.2 mph
Avg. corrected wind speed:   11.6 mph
Prevailing wind direction:   South-Southwest [16%] Peak gust and direction:  46 NE on the 22nd, W on the 31st

SUNSHINE:
Campbell-Stokes card minutes: 10506 of a possible 26226, or 40%
Astronomical total minutes: 10897 of a possible 27191 or 40%

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Today’s Observations:

7 A.M.
Weather: Clear, few altocumulus/castellanus distant W-WNW and
distant NE-SE, few cirrus distant W-N, smoke layer aloft distant
ENE-SE-SW
Temperature: 55F; Dew Point: 44F; Relative Humidity: 66%
Wind: W @ 7 kts
Sea-level pressure: 1014.2 mb; 29.95 in. Hg: rising, then more rapidly
Visibility: 70 miles
6-hr Max temp: 55F
6-hr Min temp: 48F
24-hr Precip:  Trace
BHO SA 1155 CLR 70 142/55/44/2607/995/ FEW AC/ACC DSNT W-NNW AND
DSNT NE-SE FEW CI DSNT W-N K LYR ALF DSNT ENE-SE-SW/ 8/084 53011
6000/ 70000 10055 20048

10 A.M.
Weather: Broken cumulus, broken cirrus, smoke layer aloft distant
ESE-S-WSW and distant WNW-NW
Temperature: 63F; Dew Point: 46F; Relative Humidity: 46%
Wind: WSW @ 8G17 kts
Sea-level pressure: 1014.5 mb; 29.96 in. Hg: rising, then falling
Visibility: 70 miles
3-hr Precip:  0.00 inches
BHO SA 1455 E35 BKN 250 BKN 70 145/63/46/2508G17/996/ K LYR ALF DSNT
ESE-S-WSW AND DSNT WNW-NW/ 8/201 50003

1 P.M.
Weather: Broken cumulus, broken cirrus, smoke layer aloft all
quadrants
Temperature: 65F Dew Point: 46F; Relative Humidity: 50%
Wind: W @ 10G17 kts
Sea-level pressure: 1014.0 mb; 29.94 in. Hg: steady, then falling
Visibility: 70 miles
6-hr Max temp: 69F
6-hr Min temp: 55F
6-hr Precip:  0.00 inches
BHO SA 1755 E55 BKN 250 BKN 70 140/65/46/2710G17/994/
K LYR ALF ALQDS/ 8/201 58005 10069 20055

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SUMMARY FOR SUNDAY, JUNE 1, 2025

TEMPERATURE (DEGREES F)
MAX…….63   NORMAL…..71
MIN…….47   NORMAL…..53
MEAN……55   NORMAL…..62

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-7
TOTAL DEPARTURE FOR THE MONTH……………………….-7 [-7.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….10  DEPARTURE……..+5
TOTAL HEATING UNITS FOR THE MONTH…………….10  DEPARTURE……..+5
TOTAL HEATING UNITS FOR THE SEASON………….5625  DEPARTURE……-524
TOTAL HEATING UNITS LAST SEASON TO DATE……..5379  DEPARTURE……+246

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE MONTH……………..0  DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE SEASON……………17  DEPARTURE…….-13
TOTAL COOLING UNITS LAST SEASON TO DATE……….38  DEPARTURE…….-21

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)………..40 W    @   09:14 A.M.
VECTOR #1 (1-Sec)……….41 W    @   07:59 A.M.
VECTOR #2 (1-Sec)……….43 WSW  @   08:06 A.M.
DAVIS #1……………….42 W    @   09:14 A.M.
DAVIS #2 ………………42 W    @   08:24 A.M.
RMY #1 (Instantaneous)…..42 W    @   07:58 A.M.
RMY #2 (Instantaneous)…..49 WSW  @   08:06 A.M.
MERLIN…………………39 W
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………29 W    @   10:34 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..30      @   09:14 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..31      @   08:25 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………32 W    @   09:15 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………31 W    @   08:25 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..29 W    @   07:59 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..30 W    @   08:25 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..15.5 W [371 total miles] VECTOR #1………………14.9
VECTOR #2………………15.2
DAVIS #1……………….15.6 W
DAVIS #2……………….15.4 W
RMY #1…………………14.3 W
RMY #2…………………14.9 WSW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….TRACE DEPARTURE…..-0.16
TOTAL PRECIPITATION FOR THE MONTH…………..0.01 DEPARTURE…..-0.15
TOTAL PRECIPITATION FOR THE YEAR (2025)…….21.75 DEPARTURE…..-1.01

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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/+8/0.04/0.0/474/55        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/-10/0.61/0.0/027/03       41 N   VEC1 41 N   RMY 42
5/24  60/46/53/-7/0.10/0.0/321/36        30 WNW VEC1 30 WNW RMY 31
5/25  59/47/53/-7/T/0.0/206/23           29 NW  VEC1 29 NW  RMY 31
5/26  70/45/58/-2/0.00/0.0/861/96        23 NNE VEC1 23 NNE RMY 23
5/27  79/50/65/+5/0.00/0.0/709/79        25 SSW VEC1 26 SSW RMY 26
5/28  78/55/67/+6/0.01/0.0/666/74        25 SSW VEC1 24 SSW RMY 26
5/29  65/54/60/-1/0.04/0.0/027/03        21 S   VEC1 21 S   RMY 20
5/30  74/57/66/+5/T/0.0/433/48           30 S   VEC1 32 S   RMY 30
5/31  66/47/57/-5/0.27/0.0/154/17        46 W   VEC1 46 W   RMY 49

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MAY DAILY RECORDS TO DATE

5/16 RECORD HIGH MINIMUM TEMPERATURE OF 61F;
PREVIOUS RECORD WAS 60F SET IN 2014

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PRELIMINARY CLIMATE SUMMARY FOR JUNE CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

6/1   63/47/55/-7/0.01/…/..            40 W   VEC1 40 W   RMY 42

6/2 The low since midnight is 48F, the daily normal low is 53F.

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JUNE 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 JUNE 2
HIGH 91F IN 1895
LOW 41F IN 1907, 1929
PRECIP 2.36 INS IN 1982
SNOWFALL TRACE IN 1907 (ICE PELLETS)
PEAK GUST 63 MPH NW IN 2000

RECORDS FOR JUNE 3
HIGH 98F IN 1919
LOW 38F IN 1929
PRECIP 2.40 INS 2006
PEAK GUST 47 MPH NW IN 1998

TODAY’S REPORT PREPARED BY: MFD