Friday, May 16, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
FRIDAY, MAY 16, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0421E
SUNSET: 1900E
WARM AND HUMID DAY AS MORNING FOG BURNS OFF LEAVING US WITH PARTIAL
SUNSHINE….
We started the day with dense fog here on the summit which burned
off rather quickly leaving us with just cloudy skies for the balance
of the morning hours. Some breaks of sunshine have developed early
this afternoon. The main story for today however is the rising
humidity levels as it’s felt rather muggy since yesterday. This is
our first real taste of higher dew point air this season that has
lasted more than just a few hours.
Temperatures have warmed into the mid to upper 70s early this
afternoon. As mentioned, the dew point has been holding in the mid
60s all day as well. Needless to say it feels rather muggy out there
once again today. Since the dew point held in the 60s all night, the
overnight low temperature was 61F degrees. If this value holds
through midnight tonight, this will set a new record high minimum
for today’s date. The previous record is 60F set in 2014.
Winds have been quite light most of the day, but are finally showing
signs of picking up a bit early this afternoon. The average speed
for the day so far is only around 6mph. The peak gust so far for
today is 18mph, which occurred just before 1pm.
Visibility has been gradually improving, from around 1/8th of a
mile early this morning to around 30 miles by early this afternoon.
The maximum temperature for today is 77F degrees, which is 10 degrees
above the normal high of 67F. The minimum temperature since midnight
is 61F degrees, which is 13 degrees above the normal low of 48F.
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Today’s Observations:
7 A.M.
Weather: Overcast stratus, few lower stratus fractus all quadrants
Temperature: 64F; Dew Point: 63F; Relative Humidity: 96%
Wind: SW @ 2 kts, wind light
Sea-level pressure: 1009.1 mb; 29.80 in. Hg: falling, then more rapidly
Visibility: 15 miles, thin fog
6-hr Max temp: 64F
6-hr Min temp: 61F
24-hr Precip: 0.16 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 E17 OVC 15 091/64/63/2302/980/ FEW LWR STFRA ALQDS
THN F ALQDS WND LGT/ 8/6// 58009 70016 10064 20061
10 A.M.
Weather: Overcast stratocumulus
Temperature: 69F; Dew Point: 63F; Relative Humidity: 80%
Wind: WNW @ 2 kts, wind light and variable
Sea-level pressure: 1009.2 mb; 29.80 in. Hg: rising, then steady
Visibility: 30 miles, hazy
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E17 OVC 30 092/69/63/3002/980/ HAZY WND L/V/ 8/5// 51001
1 P.M.
Weather: Broken cumulus, broken cirrus
Temperature: 76F Dew Point: 63F; Relative Humidity: 64%
Wind: SSW @ 7G16 kts
Sea-level pressure: 1008.0 mb; 29.77 in. Hg: falling, then more rapidly
Visibility: 30 miles, hazy
6-hr Max temp: 77F
6-hr Min temp: 64F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E25 BKN 250 BKN 30 080/76/63/2007G16/977/ HAZY/
8/203 58012 10077 20064
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SUMMARY FOR THURSDAY, MAY 15, 2025
TEMPERATURE (DEGREES F)
MAX…….72 NORMAL…..67
MIN…….58 NORMAL…..48
MEAN……65 NORMAL…..57
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+8
TOTAL DEPARTURE FOR THE MONTH………………………+60 [+3.8 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…….-64
TOTAL HEATING UNITS FOR THE SEASON………….5486 DEPARTURE……-553
TOTAL HEATING UNITS LAST SEASON TO DATE……..5314 DEPARTURE……+172
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……..-3
TOTAL COOLING UNITS FOR THE SEASON…………….7 DEPARTURE……..-3
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)………..20 SSE @ 08:00 A.M.
VECTOR #1 (1-Sec)……….20 SSE @ 08:00 A.M.
VECTOR #2 (1-Sec)……….20 SE @ 01:13 A.M.
DAVIS #1……………….19 SSE @ 08:00 A.M.
DAVIS #2 ………………20 SE @ 01:29 A.M.
RMY #1 (Instantaneous)…..19 SE @ 01:29 A.M.
RMY #2 (Instantaneous)…..21 SE @ 01:13 A.M.
MERLIN…………………17 SSE
RICHARDS (C5C) (Inst)…..OTS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………14 SE @ 01:32 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..15 @ 08:02 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..14 @ 01:30 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………15 SE @ 08:02 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………14 SE @ 07:51 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..14 SE @ 08:02 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..14 SE @ 07:51 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………7.5 SSE [180 total miles]
VECTOR #1……………….8.1
VECTOR #2……………….8.5
DAVIS #1………………..7.6 SSE
DAVIS #2………………..8.2 SSE
RMY #1………………….7.7 S
RMY #2………………….8.6 SSE
RICHARDS (C5C)…………..OTS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.16 DEPARTURE…..+0.04
TOTAL PRECIPITATION FOR THE MONTH…………..3.34 DEPARTURE…..+1.54
TOTAL PRECIPITATION FOR THE YEAR (2025)…….17.46 DEPARTURE…..-3.12
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/+8/0.04/0.0/474/55 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
5/16 The low since midnight is 61F, the daily normal low is 48F.
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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 16
HIGH 90F IN 1951
LOW 30F IN 1936
PRECIP 2.63 INCHES IN 1954
PEAK GUST 56e MPH NW IN 1952
RECORDS FOR MAY 17
HIGH 90F IN 2017
LOW 34F IN 1956, 1957
PRECIP 2.07 INS IN 1916
PEAK GUST 52 MPH SW IN 1967, W IN 1974
TODAY’S REPORT PREPARED BY: MFD
