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Saturday, May 9, 2026

May 9, 2026

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA SATURDAY, MAY 9, 2026 ALL TIMES ARE…

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

SATURDAY, MAY 9, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0429E
SUNSET:  1853E

PERSISTENT DRIZZLE MAKES FOR A DAMP AND CHILLY MAY DAY….

Overcast skies persisted throughout the day with periods of light
drizzle and mist continuing through the early afternoon hours.
Despite the nearly continuous damp conditions, rainfall amounts
remained minimal, totalling only 0.03″ as of 1pm. Thick cloud
cover prevented any meaningful sunshine and only contributed to
the raw feel of the day. While below normal, this is at least
better than today’s date in 1977 when the summit received a
total of 7.8″ of snow over the 9th and 10th during a late season
snow storm.

Temperatures remained below the average of 65F today, reaching
just 58F by the afternoon. Combined with the drizzle and saturated
conditions, the air felt especially chilly during the earlier part
of the day but more humid by the afternoon. Dew points remained in
the 40’s for much of the day and creeped up to 51F by 1pm.

Winds remained out of the southeast with a slight shift to the
south-southwest by the early afternoon. The average wind speed so
far for the day is around 8mph. The peak gust so far is 21mph, which
occurred at 8:47am this morning.

Visibility remained somewhat variable throughout the day, averaging
from 20-30 miles for much of the day. Fog, virga, low clouds and
persistent drizzle limited us to 10 miles near Boston at 1pm.

The maximum temperature so far today is 58F degrees, which is
7 degrees below the normal high of 65F. The minimum temperature
since midnight is 43F degrees, which is 3 degrees below the normal
low of 46F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Light drizzle, broken altocumulus, overcast cirrostratus,
few stratocumulus all quadrants
Temperature: 43F; Dew Point: 41F; Relative Humidity: 92%
Wind: SE @ 10 kts
Sea-level pressure: 1016.0 mb; 30.00 in. Hg: rising, then falling
Visibility: 30 miles, thin fog WSW-NW
6-hr Max temp: 49F
6-hr Min temp: 43F
24-hr Precip: 0.01 inches
BHO SA 1155 85 BKN 220 OVC 30L- 160/43/41/1410/000/ FEW SC ALQDS
THN F WSW-NW PCPN VRY LGT/ 8/557 50008 6001/ 70001 10049 20043

10 A.M.
Weather: Light drizzle, overcast altostratus, few stratus fractus
SSE-SW
Temperature: 52F; Dew Point: 47F; Relative Humidity: 82%
Wind: SE @ 8 kts
Sea-level pressure: 1015.1 mb; 29.98 in. Hg: falling, then more rapidly
Visibility: 30 miles, virga WSW-NNW
3-hr Precip: 0.01 inches
BHO SA 1455 140 OVC 30L- 151/52/47/1308/998/ FEW STFRA SSE-SW
PCPN VRY LGT VIRGA WSW-NNW/ 8/72/ 58009 6001/

1 P.M.
Weather: Light drizzle, overcast altostratus, few stratus fractus
all quadrants
Temperature: 55F; Dew Point: 51F; Relative Humidity: 85%
Wind: SSW @ 9 kts
Sea-level pressure: 1014.0 mb; 29.94 in. Hg: falling, then more slowly
Visibility: 20 miles, 10 miles N-NE, thin fog
6-hr Max temp: 58F
6-hr Min temp: 43F
6-hr Precip: 0.02 inches
BHO SA 1755 85 OVC 20L- 140/55/51/2009/994/ FEW STFRA ALQDS THN F ALQDS
PCPN VRY LGT VSBY 10 N-NE/ 8/72/ 56011 6002/ 10058 20043

————————————————————–

SUMMARY FOR FRIDAY, MAY 8, 2026

TEMPERATURE (DEGREES F)
MAX…….62   NORMAL…..65
MIN…….40   NORMAL…..46
MEAN……51   NORMAL…..55

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-4
TOTAL DEPARTURE FOR THE MONTH……………………….+5 [+0.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY…………….14  DEPARTURE……..+4
TOTAL HEATING UNITS FOR THE MONTH (MAY)……….80  DEPARTURE……..-8
TOTAL HEATING UNITS FOR THE SEASON………….5916  DEPARTURE…….-59
TOTAL HEATING UNITS LAST SEASON TO DATE……..5441  DEPARTURE……+475

COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH (MAY)………..0  DEPARTURE……..-3
TOTAL COOLING UNITS FOR THE SEASON…………….6  DEPARTURE………0
TOTAL COOLING UNITS LAST SEASON TO DATE………..7  DEPARTURE……..-1

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 *=Last of multiple occurrences

F420C (Official)………..33 W    @   03:11 P.M.
VECTOR #1 (1-Sec)……….33 W    @   03:11 P.M.
VECTOR #2 (1-Sec)……….34 WNW  @   01:04 P.M.
DAVIS #1……………….33 WSW  @   03:12 P.M.
DAVIS #2 ………………31 W    @   11:58 A.M.
RMY #1 (Instantaneous)…..33 W    @   03:11 P.M.
RMY #2 (Instantaneous)…..35 WNW  @   01:04 P.M.
MERLIN…………………32 W
RICHARDS (C5C) (Inst)……32 W    @   03:11 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………22 W    @   12:13 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..22 W    @   12:13 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..24 WNW  @   01:06 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………23 W    @   12:13 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………23 W    @   03:34 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 W    @   12:13 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..23 WNW  @   01:06 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………22 WNW  @   01:28 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.6 W [255 total miles] VECTOR #1………………11.2
VECTOR #2………………11.7
DAVIS #1……………….11.7 W
DAVIS #2……………….11.6 WNW
RMY #1…………………10.9 WNW
RMY #2…………………11.4 W
RICHARDS (C5C)………….11.2

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.01 DEPARTURE…..-0.11
TOTAL PRECIPITATION FOR THE MONTH (MAY)……..0.35 DEPARTURE…..-0.65
TOTAL PRECIPITATION FOR THE YEAR (2026)…….14.02 DEPARTURE…..-5.76

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……0.0
TOTAL SNOWFALL FOR THE MONTH (MAY)…………..0.0 DEPARTURE……0.0
TOTAL SNOWFALL FOR THE SEASON (2025-2026)……81.6 DEPARTURE….+11.9

————————————————————–

PRELIMINARY CLIMATE SUMMARY FOR MAY 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

5/1  63/43/53/0/0.00/769/91              26 WNW VEC1 27 NNW RMY 27
5/2  58/45/52/-2/0.04/127/15             29 SSW VEC1 29 SSW RMY 28
5/3  53/41/47/-7/T/119/14                37 NW  VEC1 36 NW  RMY 39
5/4  71/41/56/+2/0.00/775/91             46 SW  VEC1 46 SW  RMY 48
5/5  78/49/64/+9/0.00/718/84             43 SSW VEC1 43 SSW RMY 45
5/6  68/54/61/+6/0.08/146/17             43 SSW VEC1 42 SSW RMY 44
5/7  65/46/56/+1/0.22/…/..             28 WNW VEC1 27 WNW RMY 28
5/8  62/40/51/-4/0.00/…/..             33 W   VEC1 33 W   RMY 33

5/9 The low since midnight is 43F, the daily normal low is 46F.

————————————————————–

MAY 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 9
HIGH 93F IN 2000
LOW 31F IN 1947
PRECIP 2.72 INCHES IN 1954
SNOWFALL 5.0 INS IN 1977 (RECORD FOR MAY)
PEAK GUST 70e MPH NE IN 1977

RECORDS FOR MAY 10
HIGH 93F IN 1896
LOW 29F  IN 1900
PRECIP 1.85 INS IN 1998
SNOW 2.8 INS 1977 (7.8 INS TOTAL 5/9-5/10 1977)
PEAK GUST 64 MPH S IN 1990

TODAY’S REPORT PREPARED BY: Amanda Joly

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Blue Hill Observatory & Science Center · Legal

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Please read the full Policy before accessing Observatory data · Effective January 1, 2025

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Effective January 1, 2025 · Milton, Massachusetts · bluehill.org
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