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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, AUGUST 18, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

DECREASING CLOUDS WITH LOW VISIBILITY AND MUGGY 
CONDITIONS ON TOP OF THE GREAT BLUE HILL…

Mostly cloudy during the morning hour with 
decreasing cloud cover as the day progressed. 
Visibly was poor with 35 miles being observed 
throughout all three observation periods. It has 
been muggy all day with dew points staying in 
the low 70’s. The high so far today is 86F, 7 
degrees above the daily normal maximum of 79F. 
The low since midnight is 71F, 9 degrees above 
the average daily minimum of 62F. 


PRELIMINARY STATS FOR JULY 2019

TEMPERATURE, Deg. F
Avg. Max. 84.6 [+3.8]
Avg. Min. 65.6 [+2.7]
Mean      75.1 [+3.2]
24-hour corrected mean: 74.5
Max. for month: 93F on the 20th, 30th
Min. for month: 58F on the 1st, 23rd

COOLING DEGREE DAYS
Total cooling units:   322 [+100]
Total for the season:  411 [+60]
Total for last season: 455

PRECIPITATION, Inches
Total: 5.45 [+1.43]
Greatest in 24 hrs: 2.08 on the 22nd-23rd 

WIND, mph
Avg. uncorrected wind speed: 8.8
Avg. corrected wind speed:   9.6
Prevailing wind direction: W at 14%
Peak gust and direction: 44 W on 17th  

SUNSHINE:
Campbell-Stokes card minutes: 18300 minutes of possible 26682 or 69%
Astronomical total minutes: 19049 minutes of possible 27759 or 69%

Today's Observations:

7 A.M.
Weather: broken stratus
Temperature: 71F; Dew Point: 70F; Wind: WSW at 2 kts (estimated),
Wind: light and variable
Sea-level pressure: 30.02 ins. Hg, falling, then rising
Visibility: 35 miles
6-hr Max temp: 71F
6-hr Min temp: 70F
24-hr Precip: 0.01 ins.
BHO SA 1155 E10 BKN 35 168/71/70/2502/002/ WND L/V/ 8/6// 
53012 10071 20070

10 A.M.
Weather: Few cumulus, scattered altocumulus, broken cirrostratus
Temperature: 79F; Dew Point: 73F; Wind: NNW at 4 kts (estimated),
Wind: light and variable
Sea-level pressure: 30.02 ins. Hg, rising, then falling
Visibility: 35 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E220 SCT E250 BKN 35 168/79/73/3404/002/ 
FEW CU ALQDS WND L/V/ 8/166 50001

1 P.M.
Weather: Few cumulus, scattered altocumulus, broken cirrostratus
Temperature: 86F; Dew Point: 70F; Wind: NW at 5 kts
Wind: light and variable
Sea-level pressure: 30.00 ins. Hg, falling, then rising
Visibility: 35 miles
6-hr Max temp: 86F
6-hr Min temp: 71F
6-hr Precip: 0.00 ins.
BHO SA 1755 E220 SCT E250 BKN 35 162/86/70/3105/000/ 
FEW CU ALQDS WND L/V/ 8/166 55006 10086 20071

SUMMARY FOR SATURDAY, AUGUST 17, 2019 

TEMPERATURE (DEGREES F)
MAX.....78   NORMAL.....79
MIN.....67   NORMAL.....62
MEAN....73   NORMAL.....71

DEPARTURE FROM 30-YEAR NORMAL......................+2
TOTAL DEPARTURE FOR THE MONTH......................+4 [0.0 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............8   DEPARTURE.........+3
TOTAL COOLING UNITS FOR THE MONTH.............115   DEPARTURE.........0
TOTAL COOLING UNITS FOR THE SEASON............526   DEPARTURE........+60
TOTAL COOLING UNITS LAST SEASON TO DATE.......653   DEPARTURE.......-127

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................14 SE  AT 7:28 P.M.
                   AERO.........................15 SE  AT 4:07 P.M.
                   ASOS.........................15 SSE AT 4:20 P.M.
                   DAVIS........................16 SSE AT 4:16 P.M. RMY 15
FASTEST MILE FOR YESTERDAY......................12 SE  AT 9:26 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...................10 SE  AT 9:57 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................12 SSE AT 9:35 P.M.
AVERAGE WIND SPEED AND DIRECTION..............5.5  SSE
                   ASOS.......................5.9
                   DAVIS......................6.0 SSE [153 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..........0.83  DEPARTURE......-1.54
                         ASOS..............0.82
TOTAL PRECIPITATION FOR THE YEAR..........36.15  DEPARTURE......+2.79
                         ASOS.............36.10

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 83/58/71/+1/0.00/896/98               21 NNW AERO 21 NNW RMY N/A
07/02 82/65/74/+4/0.00/329/36               23 W   AERO 23 W   RMY 23
07/03 89/67/78/+7/0.00/866/95               18 S   AERO 18 S   RMY 18
07/04 88/68/78/+7/0.00/748/82               17 SSW AERO M  M   RMY 17
07/05 87/69/78/+7/0.00/829/91               21 SW  AERO M  M   RMY 21
07/06 90/71/81/+10/0.83/646/71              26 WNW AERO M  M   RMY N/A TSTM
07/07 78/64/71/0/0.00/827/91                30 NE  AERO M  M   RMY N/A
07/08 79/59/69/-3/0.00/763/84               16 N   AERO 18 SSW RMY N/A
07/09 85/61/73/+1/0.00/871/96               18 NW  AERO 16 NW  RMY 18
07/10 88/69/79/+7/0.00/607/67               20 ESE AERO 16 ESE RMY 17
07/11 81/67/74/+2/0.62/000/00               35 S   AERO 33 S   RMY 36
07/12 84/68/76/+4/0.00/316/35               31 WNW AERO 30 WNW RMY 32
07/13 85/65/75/+3/0.00/812/90               21 W   AERO 20 WSW RMY 20
07/14 87/68/78/+6/0.00/702/78               25 W   AERO 21 W   RMY 23
07/15 82/63/73/+1/0.00/791/88               24 WNW AERO 23 WNW RMY 22
07/16 86/65/76/+4/0.00/682/76               23 W   AERO 21 W   RMY 21
07/17 90/70/80/+8/1.32/260/29               44 W   AERO M  M   RMY 47 TSTM
07/18 72/61/67/-5/0.04/000/00               33 NE  AERO 36 NE  RMY 33
07/19 89/61/75/+3/0.00/580/65               24 WSW AERO 26 SW  RMY 25
07/20 93/75/84/+12/0.00/802/90              21 WSW AERO 22 WSW RMY N/A
07/21 92/76/84/+12/0.00/729/82              31 W   AERO 35 W   RMY 31
07/22 81/64/73/+1/1.22/284/32               35 ENE AERO 37 ENE RMY 34
07/23 66/58/62/-10/0.86/009/01              30 NNE AERO 33 NNE RMY 30
07/24 77/60/69/-3/0.01/575/65               14 NE  AERO 15 NE  RMY N/A
07/25 80/61/71/-1/0.00/732/83               17 SSE AERO 23 N   RMY 17
07/26 84/62/73/+1/0.00/730/83               22 SSE AERO 23 SSE RMY 20
07/27 83/64/74/+2/0.00/834/95               21 S   AERO 23 S   RMY 21
07/28 89/64/77/+5/0.00/710/81               25 WSW AERO 36 WSW RMY 26
07/29 89/71/80/+8/0.01/804/92               23 W   AERO 25 W   RMY 21
07/30 93/71/82/+10/0.00/767/88              24 S   AERO 24 S   RMY 23
07/31 90/68/79/+7/0.55/548/63               37 SW  AERO 35 SW  RMY 38 TSTM

DAILY RECORDS FOR JULY 2019

7/20/19: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 75F,
BREAKS PREVIOUS RECORD OF 73F SET IN 1977, 2015

7/21/19: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 76F,
BREAKS PREVIOUS RECORD OF 75F SET IN 1991


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

8/01  84/66/75/+3/0.00/755/87               18 NNW AERO 20 NW  RMY 17
8/02  83/61/72/0/0.00/804/93                18 WSW AERO 18 WSW RMY 18 
8/03  84/66/75/+3/0.00/302/35               25 SW  AERO 26 SW  RMY 25
8/04  83/66/75/+3/0.00/732/85               21 NE  AERO 23 SW  RMY 25
8/05  81/58/70/-2/0.00/842/98               20 S   AERO 18 S   RMY 19
8/06  79/63/71/-1/0.00/282/33               15 S   AERO 14 S   RMY 17
8/07  82/66/74/+2/..../367/43               32 SSW AERO 35 SSW RMY 35
8/08  84/67/76/+4/..../588/69               30 SW  AERO 24 WNW RMY 29
8/09  82/63/73/+1/..../815/96               28 NW  AERO 25 NW  RMY 26
8/10  78/59/69/-2/..../669/79               32 NW  AERO 28 NW  RMY 28
8/11  78/55/67/-4/0.00/.../..               28 W   AERO 25 W   RMY 28
8/12  82/60/71/0/0.00/.../..                25 W   AERO 23 W   RMY 26
8/13  77/66/72/+1/0.02/.../..               25 W   AERO 24 WSW RMY 24
8/14  75/62/69/-2/..../.../..               24 ENE AERO 22 ENE RMY 22
8/15  77/59/68/-3/..../.../..               17 ESE AERO 15 SSE RMY 16
8/16  78/61/70/-1/..../../..                20 E   AERO 17 ESE RMY 18
8/17  78/67/73/2/..../../..                 14 SE  AERO 15 SE  RMY 15

8/18 Low temp since midnight is 68F; normal low is 62F


DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR AUGUST 18
HIGH 93F IN 2002
LOW 47F IN 1824
PRECIP 5.75 INCHES IN 1955 [DIANE]
PEAK GUST 46 MPH WNW IN 2007

RECORDS FOR AUGUST 19
HIGH 90F IN 1906, 1966, 2002
LOW 48F IN 1958
PRECIP 7.02 INCHES IN 1955 [DIANE - RECORD FOR MONTH]
PEAK GUST 78 MPH ENE IN 1991 – HURRICANE BOB

TODAY'S REPORT PREPARED BY: Nicholas Rousseau