Sunday, May 18, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SUNDAY, MAY 18, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0420E
SUNSET: 1902E
SUNNY START TO THE DAY WITH INCREASING CLOUDS AND WIND BY
THE AFTERNOON….
Today started with brilliant blue skies and scattered clouds and a
steady breeze from the west and west-northwest. As the temperatures
began to heat up, clouds also began to increase as a small system
slowly moved into the area. As of the 1pm observation we had no
precipitation, but there was rain seen just a few miles from the
observatory to our west and northwest.
Temperatures have been in the low to mid 60’s for much of the day,
with a brief spike in the upper 60’s before the increasing clouds
and higher winds moved through.
Winds have been fairly steady out of the west and west-northwest,
mostly picking up during the late morning and early afternoon hours.
The average speed for the day so far is around 14mph. The peak gust
so far for today is 34mph, which occurred just after 12:OOpm this
afternoon.
Visibility has held steady between 40-50 miles today, mostly due to
pollen and higher dew points. By this afternoon, the visibility was
impacted due to distant rain in the region as well as a brush fire
to our east.
The maximum temperature for today is 68F degrees, which is 1 degree
above the normal high of 67F. The minimum temperature since midnight
is 55F degrees, which is 6 degrees above the normal low of 49F.
————————————————————–
Today’s Observations:
7 A.M.
Weather: Scattered altocumulus, few cumulus all quadrants
Temperature: 60F; Dew Point: 52F; Relative Humidity: 74%
Wind: WNW @ 9 kts
Sea-level pressure: 1000.1 mb; 29.53 in. Hg: rising, then falling
Visibility: 50 miles
6-hr Max temp: 60F
6-hr Min temp: 55F
24-hr Precip: Trace
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 150 SCT 50 001/60/52/2809/953/ FEW CU ALQDS/ 8/250 50009
70000 10060 20055
10 A.M.
Weather: Broken cumulus, broken altocumulus
Temperature: 65F; Dew Point: 51F; Relative Humidity: 60%
Wind: WSW @ 12G19 kts, peak wind WNW 32 mph at 9:47 A.M.
Sea-level pressure: 999.3 mb; 29.51 in. Hg: falling, then more slowly
Visibility: 50 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E30 BKN 95 BKN 50 993/65/51/2812G19/951/ PK WND 2828/47/
8/250 56008
1 P.M.
Weather: Overcast stratocumulus, few breaks in overcast E-ESE, virga
W-WNW-N
Temperature: 65F Dew Point: 51F; Relative Humidity: 61%
Wind: W @ 16G23 kts, peak wind WNW 31 mph at 12:10 P.M.
Sea-level pressure: 998.5 mb; 29.49 in. Hg: falling, then more slowly
Visibility: 40 miles, smoke plume East
6-hr Max temp: 68F
6-hr Min temp: 60F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E55 OVC 40 985/65/51/2716G23/949/ FEW BINOVC E-ESE
VIRGA W-WNW-N K PLUME E PK WND 2827/10/ 8/5// 56008 10068 20060
————————————————————–
SUMMARY FOR SATURDAY, MAY 17, 2025
TEMPERATURE (DEGREES F)
MAX…….76 NORMAL…..67
MIN…….58 NORMAL…..49
MEAN……67 NORMAL…..58
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………+9
TOTAL DEPARTURE FOR THE MONTH………………………+81 [+4.6 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………..0 DEPARTURE……..-8
TOTAL HEATING UNITS FOR THE MONTH…………….88 DEPARTURE…….-80
TOTAL HEATING UNITS FOR THE SEASON………….5486 DEPARTURE……-569
TOTAL HEATING UNITS LAST SEASON TO DATE……..5332 DEPARTURE……+154
COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..2 DEPARTURE……..+1
TOTAL COOLING UNITS FOR THE MONTH…………….11 DEPARTURE……..+2
TOTAL COOLING UNITS FOR THE SEASON……………14 DEPARTURE……..+2
TOTAL COOLING UNITS LAST SEASON TO DATE………..2 DEPARTURE…….+12
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)………..30 S @ 04:45 P.M.
VECTOR #1 (1-Sec)……….29 S @ 04:45 P.M.
VECTOR #2 (1-Sec)……….30 SSW @ 03:45 P.M.
DAVIS #1……………….33 S @ 04:45 P.M.
DAVIS #2 ………………38 S @ 04:48 P.M.
RMY #1 (Instantaneous)…..30 S @ 04:46 P.M.
RMY #2 (Instantaneous)…..31 SSE @ 03:45 P.M.
MERLIN…………………27 SSW
RICHARDS (C5C) (Inst)…..OTS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………21 S @ 04:47 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..21 @ 04:55 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..22 @ 05:36 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 S @ 04:55 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………27 S @ 04:49 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..20 SSW @ 05:35 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..22 S @ 04:47 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..12.0 SSW [287 total miles]
VECTOR #1………………12.1
VECTOR #2………………13.0
DAVIS #1……………….11.7 SSW
DAVIS #2……………….13.3 SSW
RMY #1…………………11.8 SSW
RMY #2…………………13.0 SSW
RICHARDS (C5C)…………..OTS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….TRACE DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH…………..3.34 DEPARTURE…..+1.31
TOTAL PRECIPITATION FOR THE YEAR (2025)…….17.46 DEPARTURE…..-3.35
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/+8/0.04/0.0/474/55 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
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/…/.. 30 S VEC1 29 S RMY 30
5/18 The low since midnight is 55F, the daily normal low is 49F.
————————————————————–
MAY DAILY RECORDS TO DATE
5/16 RECORD HIGH MINIMUM TEMPERATURE OF 61F;
PREVIOUS RECORD WAS 60F SET IN 2014
————————————————————–
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR MAY 18
HIGH 96F IN 2017(RECORD FOR MAY)
LOW 35F IN 2002
PRECIP 1.93 INS IN 2007
SNOW TRACE IN 2002 (Ice pellets)
PEAK GUST 64 MPH SSW IN 2000
RECORDS FOR MAY 19
HIGH 91F IN 1962
LOW 34F IN 2002
PRECIP 1.54 INCHES IN 1900
PEAK GUST 58 MPH NW IN 1964
TODAY’S REPORT PREPARED BY: Amanda Joly
