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BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SATURDAY, SEPTEMBER 12, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME
A COOL, FAIR WEATHER DAY WITH A LIGHT
NORTHEASTERLY WIND….
Today we observed mostly clear skies with good visibility
for the most part. A thin smoke layer kept visibility
down to 45 miles this morning, but a max visibility of
80 miles was seen later in the day. Cloud cover increased
by 1 P.M., with half the sky being covered by cumulus and
cirrus clouds.
A cooler air mass carried in by a high pressure system
has left conditions on the cooler side, this is in
conjunction with a light sea breeze from the northeast.
The high since midnight is 68F, 5 degrees below the daily
normal max of 73F. The low since midnight is 51F, which
is 5 degrees below the normal low of 56F.
PRELIMINARY STATS FOR AUGUST 2020
TEMPERATURE, Deg. F
Avg. Max. 82.5 [+3.3]
Avg. Min. 64.3 [+2.5]
Mean 73.4 [+2.9]
24-hour corrected mean: 72.3
Max. for month: 94F on the 10th
Min. for month: 54F on the 31st
HEATING DEGREE DAYS
Total heating units: 2 [-14]
Total for the season: 3 [-22]
Total for last season: 12
COOLING DEGREE DAYS
Total cooling units: 270 [+84]
Total for the season: 757 [+220]
Total for last season: 622
PRECIPITATION, Inches
Total: 3.74 [-0.29]
Greatest in 24 hrs: 2.21 ins. on the 23rd
WIND, mph
Avg. uncorrected wind speed: 10.0 mph
Avg. corrected wind speed: 10.6 mph
Prevailing wind direction: SSW [12%]
Peak gust and direction: 67 SSE on the 4th
SUNSHINE:
Campbell-Stokes card minutes: 15366 minutes of a possible 24780 or 62%
Astronomical total minutes: 15940 minutes of a possible 25709 or 62%
Today’s Observations:
7 A.M.
Weather: Clear, few cumulus and cirrus
Temperature: 55F; Dew Point: 51F; Relative Humidity: 86%
Wind: NNE at 7 kts
Sea-level pressure: 30.37 ins. Hg: rising, then rising more slowly
Visibility: 40 miles, thin smoke layer NW-SW
6-hr Max temp: 56F
6-hr Min temp: 51F
24-hr Precip: 0.01 ins.
BHO SA 1155 CLR 40 283/55/51/0307/037/ FEW CU/CI ALQDS THN K LYR NW-SW/
8/101 70001 53013 10056 20051
10 A.M.
Weather: Clear, few cumulus and cirrus
Temperature: 65F; Dew Point: 48F; Relative Humidity: 53%
Wind: ENE at 10G18 kts
Sea-level pressure: 30.39 ins. Hg: rising, then rising more slowly
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 80 289/65/48/0610G18/039/ FEW CU/CI ALQDS/ 8/101 53006
1 P.M.
Weather: Scattered cumulus, broken cirrus
Temperature: 65F; Dew Point: 48F; Relative Humidity: 54%
Wind: ENE at 7G15 kts
Sea-level pressure: 30.37 ins. Hg: falling, then more slowly
Visibility: 75 miles
6-hr Max temp: 68F
6-hr Min temp: 55F
6-hr Precip: 0.00 ins.
BHO SA 1755 40 SCT 250 BKN 75 283/65/48/0607G15/037/ 8/101 58006
10068 20055
SUMMARY FOR FRIDAY, SEPTEMBER 11, 2020
TEMPERATURE (DEGREES F)
MAX…..72 NORMAL…..73
MIN…..55 NORMAL…..56
MEAN….64 NORMAL…..65
DEPARTURE FROM 30-YEAR NORMAL……………. -1
TOTAL DEPARTURE FOR THE MONTH……………. +29 [+2.4 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..1 DEPARTURE……-1
TOTAL HEATING UNITS FOR THE MONTH…………..2 DEPARTURE…..-17
TOTAL HEATING UNITS FOR THE SEASON………….4 DEPARTURE…..-39
TOTAL HEATING UNITS LAST SEASON TO DATE……..5 DEPARTURE…..-23
COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY………… 0 DEPARTURE……-3
TOTAL COOLING UNITS FOR THE MONTH………… 48 DEPARTURE…..+13
TOTAL COOLING UNITS FOR THE SEASON………..805 DEPARTURE….+233
TOTAL COOLING UNITS LAST SEASON TO DATE……642 DEPARTURE….+163
PEAK WIND GUST FOR YESTERDAY (MPH)
420C/Official…………….25 N AT 5:29 A.M.
AERO…………………….25 N AT 5:29 A.M.
ASOS…………………….23 N AT 6:25 A.M.
DAVIS……………………24 N AT 6:25 A.M.
RMY n/a MERLIN n/a
FASTEST MILE FOR YESTERDAY………………….16 N AT 6:42 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 ENE AT 8:21 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………16 ENE AT 8:21 A.M.
AVERAGE WIND SPEED AND DIRECTION……………9.4 ENE
ASOS……………………9.7
DAVIS…………………..9.9 NE [47 deg.]
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.01 DEPARTURE….-0.12
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.52 DEPARTURE….-0.83
ASOS…………..0.51
TOTAL PRECIPITATION FOR THE YEAR……….33.33 DEPARTURE….-3.04
ASOS………….34.09
PRELIMINARY CLIMATE SUMMARY FOR AUGUST CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY: R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M: Missing data
08/01 87/66/77/+5/0.00/866/100 18 S AERO 21 S RMY 19
08/02 85/69/77/+5/0.02/320/37 36 S AERO 37 S RMY 38
08/03 91/75/83/+11/0.00/715/83 36 WSW AERO 38 SW RMY 36
08/04 83/71/77/5/0.21/094/11 67 SSE AERO 71 S RMY 70
08/05 90/68/79/+7/0.00/668/78 28 SW AERO 30 SW RMY 29
08/06 84/65/75/3/0.00/701/82 20 W AERO 17 W RMY 19
08/07 79/65/72/0/T/136/16 16 NE AERO 16 NE RMY N/A
08/08 83/64/74/+2/0.00/612/72 20 S AERO 20 S RMY 19
08/09 90/65/78/+6/0.00/661/78 26 SSW AERO 26 SSW RMY 26
08/10 94/69/82/+11/0.00/727/86 22 W AERO 20 W RMY 20
08/11 92/72/82/+11/0.00/708/84 31 SSW AERO 35 SSW RMY 31 TSTM
08/12 93/74/84/+13/0.00/647/77 22 SSW AERO 22 SW RMY 19
08/13 88/71/80/+9/0.00/528/63 18 ENE AERO 18 NE RMY 18
08/14 82/67/75/+4/0.00/618/74 23 ENE AERO 23 ENE RMY N/A
08/15 67/62/65/-6/T/000/00 33 NNE AERO 32 NNE RMY N/A
08/16 69/62/66/-5/0.34/000/00 26 ENE AERO 28 ENE RMY 26
08/17 73/59/66/-5/0.04/339/41 25 NE AERO 24 NE RMY N/A
08/18 84/63/74/+3/0.23/784/95 23 W AERO 23 W RMY 24
08/19 81/59/70/0/0.03/526/64 26 W AERO 28 W RMY 27
08/20 80/56/68/-2/0.00/804/98 22 W AERO 21 W RMY 22
08/21 88/61/75/+5/0.00/719/88 28 SW AERO 26 SW RMY 28
08/22 85/66/76/+6/0.26/521/64 18 NNE AERO 16 S RMY 16
08/23 89/63/76/+6/2.21/552/68 60 WNW AERO 53 WNW RMY 58 TSTM HAIL
08/24 87/67/77/+7/0.00/493/61 18 S AERO 18 S RMY 19 TSTM
08/25 86/65/76/+7/0.01/492/61 35 NNW AERO 37 NNW RMY 35
08/26 74/56/65/-4/0.00/780/97 29 NW AERO 32 NW RMY N/A
08/27 68/57/63/-6/0.33/008/01 18 SSE AERO 20 SSE RMY 20 TSTM
08/28 80/59/70/+1/0.00/559/70 20 W AERO 20 W RMY N/A
08/29 74/65/70/+1/0.06/000/00 32 W AERO 32 W RMY N/A
08/30 75/57/66/-2/0.00/793/100 36 W AERO 36 W RMY N/A
08/31 75/54/65/-3/0.00/569/72 20 S AERO 20 S RMY 20
DAILY RECORDS FOR AUGUST 2020
8/23/20: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 89F,
BREAKS PREVIOUS RECORD of 88F SET IN 1918, 1947, 1949, 1996
8/23/20: DAILY RECORD PRECIPITATION OF 2.21 INS,
BREAKS PREVIOUS RECORD OF 2.09 INS SET IN 2010
8/23/20: DAILY RECORD PEAK WIND GUST OF 60 MPH,
TIES PREVIOUS RECORD OF 60 MPH SET IN 1940
PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY: R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M: Missing data
09/01 76/59/68/0/0.00/…/.. 22 SSE AERO 21 SE RMY 20
09/02 69/59/64/-4/…/…/.. 23 SSE AERO 23 SSE RMY 24
09/03 75/66/71/+4/…/…/.. 22 SSW AERO 21 SSW RMY n/a
09/04 82/62/72/+5/0.00/…/.. 26 WNW AERO 26 WNW RMY 25
09/05 76/55/66/-1/0.00/…/.. 25 W AERO 25 W RMY 24
09/06 78/58/68/+1/0.00/…/.. 24 W AERO 24 W RMY n/a
09/07 79/61/70/+4/0.00/…/.. 27 SSE AERO 30 SSE RMY 28
09/08 82/61/72/+6/0.00/…/.. 17 S AERO 16 S RMY 17
09/09 80/62/71/+5/0.00/…/.. 16 S AERO 15 S RMY 16
09/10 81/69/75/+10/0.29/…/.. 21 SSW AERO 21 SSW RMY n/a
09/11 72/55/64/-1/0.01/…/.. 25 N AERO 25 N RMY N/A
09/12 The low since midnight is 51F, the daily normal low is 56F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR SEPTEMBER 12
HIGH 92F IN 1961
LOW 42F IN 1958,1967,1985
PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA)
PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA)
RECORDS FOR SEPTEMBER 13
HIGH 91F IN 1957
LOW 40F IN 1985
PRECIP 3.10 INCHES IN 1987
PEAK GUST 44 MPH WNW IN 1986
TODAY’S REPORT PREPARED BY: Benjamin Turner
