Friday, July 31, 2020
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
FRIDAY, JULY 31, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME
COOLER, SUNNIER CONDITIONS RETURN TO GREAT
BLUE HILL…
After a week featuring several 90+ degree heat
and muggy conditions, we have returned to more
normal temperatures atop the hill. As of the 1PM
observation, we have achieved “only” 83 degrees
for the daily high. Dew points began in the low-
60s slipping to the upper-50s by early afternoon.
The refreshing temperatures were accompanied by
gradually clearing skies and excellent visibility
around 80 miles.
As we round out July, a review of 90+ degree days
so far this year indicates a total of 7. Per our
Chief Scientist, Mike Iacono, “the full record mean
(1885-2019) number of days is 6 for the year, but
the most recent 30-year average is 9 for the year,
so it’s increasing”. The most ever recorded during
the year was 23 back in 1949 and in 2002.
The high so far today is 83 degrees. This is 2
degrees above the daily normal high of 81F. The
low since midnight is 69F, which is 6 degrees
above the daily normal low of 63F
Today’s Observations:
7 A.M.
Weather: Broken Altocumulus/Altostratus, few stratus
distant SE-S, FEW CI SW-NE
Temperature: 70F; Dew Point: 61F; Relative Humidity: 73%
Wind: NW at 5 kts (wind light)
Sea-level pressure: 29.84 ins. Hg: rising, then more rapidly
Visibility: 80 miles (30 SE-S)
6-hr Max temp: 72F
6-hr Min temp: 69F
24-hr Precip: 0.00 ins.
BHO SA 1155 E130 BKN 80 106/70/61/3205/984/ FEW ST DSNT
SE-S FEW CI SW-NE VSBY 30 SE-S WND LGT/ 8/752 53009
10072 20069
10 A.M.
Weather: Scattered Altocumulus/Altostratus, few stratus
SE-SW, few cumulus W-N, few cirrus SW-NE
Temperature: 77F; Dew Point: 62F; Relative Humidity: 61%
Wind: NW at 4 kts (wind light)
Sea-level pressure: 29.85 ins. Hg: falling, then rising
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 140 SCT 80 107/77/62/3204/985/ FEW ST SE-SW
FEW CU W-N FEW CI SW-NE WND LGT/ 8/252 50001
1 P.M.
Weather: Scattered Cumulus, Scattered Altocumulus/Altostratus,
few cirrus E-W
Temperature: 83F; Dew Point: 59F; Relative Humidity: 45%
Wind: N at 6 kts (wind light)
Sea-level pressure: 29.81 ins. Hg: falling, then more rapidly
Visibility: 75 miles
6-hr Max temp: 83F
6-hr Min temp: 70F
6-hr Precip: 0.00 ins.
BHO SA 1755 45 SCT 140 SCT 75 096/83/59/3506/981/ FEW CI E-W
WND LGT/ 8/252 58011 10083 20070
SUMMARY FOR THURSDAY, JULY 30, 2020
TEMPERATURE (DEGREES F)
MAX…..88 NORMAL…..81
MIN…..71 NORMAL…..63
MEAN….80 NORMAL…..72
DEPARTURE FROM 30-YEAR NORMAL………………+8
TOTAL DEPARTURE FOR THE MONTH……………..+92 [+2.9 DEGREES/DAY]
COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………15 DEPARTURE…….+8
TOTAL COOLING UNITS FOR THE MONTH…………..291 DEPARTURE……+76
TOTAL COOLING UNITS FOR THE SEASON………….475 DEPARTURE…..+131
TOTAL COOLING UNITS LAST SEASON TO DATE……..397 DEPARTURE……+78
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..29 W AT 1:56 P.M.
AERO…………………….28 W AT 1:56 P.M.
ASOS…………………….29 W AT 1:56 P.M.
DAVIS……………………29 W AT 1:56 P.M
RMY 29 MERLIN 26
FASTEST MILE FOR YESTERDAY………………….20 W AT 1:24 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….21 W AT 1:22 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………21 W AT 1:22 P.M.
AVERAGE WIND SPEED AND DIRECTION……………9.0 WSW
ASOS……………………9.2
DAVIS…………………..9.3 WSW [255 deg.]
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……0.00 DEPARTURE……-0.15
ASOS…………….0.00
TOTAL PRECIPITATION FOR THE MONTH…………1.72 DEPARTURE……-2.15
ASOS…………….1.80
TOTAL PRECIPITATION FOR THE YEAR…………29.07 DEPARTURE……-1.77
ASOS……………29.81
PRELIMINARY CLIMATE SUMMARY FOR JULY 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
07/01 76/63/70/0/0.00/228/25 16 E AERO 14 E RMY 14 TSTM
07/02 86/61/74/4/0.00/803/88 30 WSW AERO 25 WSW RMY 33
07/03 73/60/67/-4/0.00/091/10 30 NE AERO 28 NE RMY 30
07/04 79/60/70/-1/0.00/565/62 16 S AERO 16 S RMY 16
07/05 83/63/73/+2/0.54/373/41 24 NW AERO 30 NW RMY 26 TSTM
07/06 73/60/67/-4/0.00/482/53 20 ENE AERO 16 NNE RMY 18
07/07 78/60/69/-2/0.00/454/50 25 S AERO 25 S RMY 26
07/08 83/64/74/+2/0.00/227/25 32 SSW AERO 32 SSW RMY 32
07/09 89/70/80/+8/0.00/834/92 24 S AERO 23 S RMY 22
07/10 83/70/77/+5/0.05/109/12 30 SSE AERO 32 SSE RMY N/A
07/11 85/70/78/+6/0.00/614/68 39 S AERO 39 S RMY 38
07/12 86/70/78/+6/0.00/830/92 28 WSW AERO 28 WSW RMY 29
07/13 82/69/76/+4/0.23/306/34 30 SSE AERO 31 SSE RMY 30 TSTM
07/14 78/63/71/-1/0.00/369/41 26 ENE AERO 25 ENE RMY 26
07/15 72/59/66/-6/0.00/539/60 21 NE AERO 21 NE RMY N/A
07/16 73/57/65/-7/0.00/815/91 21 E AERO 21 E RMY 19
07/17 71/57/64/-8/0.19/027/03 24 SSW AERO 24 SSW RMY 25
07/18 89/66/78/+6/0.00/822/92 18 W AERO 17 W RMY 19
07/19 92/69/81/+9/0.00/…/.. 28 S AERO 28 S RMY 26
07/20 91/72/82/+10/T/…/.. 25 SSW AERO 25 SSW RMY N/A
07/21 88/68/78/+6/0.00/…/.. 25 W AERO 25 W RMY 24
07/22 80/67/74/+2/…./…/.. 16 ENE AERO M M RMY 16
07/23 88/68/78/+6/0.48/…/.. 31 N AERO 32 N RMY 31 TSTM
07/24 81/68/75/+3/0.00/…/.. 15 ENE AERO 15 ENE RMY 16
07/25 88/67/78/+6/0.00/…/.. 18 W AERO 18 WNW RMY N/A
07/26 89/70/80/+8/0.00/…/.. 27 W AERO 28 W RMY 27
07/27 94/72/83/+11/0.00/…/.. 23 SW AERO 25 SW RMY N/A
07/28 95/74/85/+13/0.01/…/.. 28 WSW AERO 25 WSW RMY 25
07/29 90/68/79/+7/0.00/…/.. 23 SSW AERO 25 SSW RMY 24
07/30 88/71/80/+8/0.00/…/.. 29 W AERO 28 W RMY 29
07/31 The low since midnight is 69F, the daily normal low is 63F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR JULY 31
HIGH 95F IN 1917
LOW 50F IN 1895,1918
PRECIP 1.34 INS IN 1892
PEAK GUST 43e MPH WNW SW IN 1953, 43 SW IN 1971
RECORDS FOR AUGUST 1
HIGH 97F IN 1917
LOW 49F IN 1891
PRECIP 3.61 INCHES IN 1927
PEAK GUST 41 MPH NNW IN 1985
TODAY’S REPORT PREPARED BY: Andrew Swanson
