BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA FRIDAY, JULY 17, 2020 ALL TIMES ARE IN EASTERN STANDARD TIME A COOL & DREARY FRIDAY ATOP GREAT BLUE HILL... We arrived on the summit early this morning under overcast skies and rather chilly temperatures. At times, the summit was socked in low, passing clouds making visibility extremely limited. A quick downpour then rolled through the area just before the 7AM observation and exited minutes after the observation window! The storm produced 0.19 inches in total of beneficial rainfall. Overcast skies persisted for the remainder of the day with visibility fluctuating between 15 to 30 miles thanks to thin distant fog.  Winds have remained generally light at around 9-12 MPH on average. Today is yet again on the cooler side, reaching 67 degrees by 1 P.M. This is 14 degrees below the daily normal high of 81F. The low since midnight is 57F, which is 5 degrees below the daily normal low of 63F. PRELIMINARY STATS FOR JUNE 2020 TEMPERATURE, Deg. F Avg. Max. 78.0 [+3.0] Avg. Min. 59.1 [+2.0] Mean      68.6 [+2.5] 24-hour corrected mean: 67.5 Max. for month: 90F on the 20th Min. for month: 42F on the 1st HEATING DEGREE DAYS Total heating units:     40 [-33] Total for the season:  5852 [-402] Total for last season: 6254 COOLING DEGREE DAYS Total cooling units:    152  [+47] Total for the season:   184  [+55] Total for last season:  89 PRECIPITATION, Inches Total: 7.56 [+3.25] Greatest in 24 hrs: 4.71 inches on the 28th-29th WIND, mph Avg. uncorrected wind speed: 9.1 mph Avg. corrected wind speed:   9.8 mph Prevailing wind direction:   S [15%] Peak gust and direction:     55 SW on the 6th SUNSHINE: Campbell-Stokes card minutes: 15996 minutes of a possible 26376 or 61% Astronomical total minutes: 16650 minutes of a possible 27422 or 61% Today's Observations: 7 A.M. Weather: Sky partially obscured, overcast stratus fractus, moderate rain Temperature: 58F; Dew Point: 57F; Relative Humidity: 97% Wind: SE at 7 kts Sea-level pressure: 30.24 ins. Hg: rising, then falling Visibility: 5 miles, fog (visibility 1 mile N to S) 6-hr Max temp: 59F 6-hr Min temp: 57F 3-hr Precip: 0.18 ins. 24-hr Precip: 0.18 ins. BHO SA 1155 –X E1 OVC 5RF 240/58/57/1407/024/ STFRA OCCLY DRFTG OVR SMT VSBY N-S 1 RB30/ 8/6// 50006 60018 70018 10059 20057 10 A.M. Weather: Overcast Stratus Fractus Temperature: 60F; Dew Point: 59F; Relative Humidity: 95% Wind: SSE at 8 kts Sea-level pressure: 30.19 ins. Hg: falling unsteadily Visibility: 30 miles, thin fog 3-hr Precip: 0.01 ins. BHO SA 1455 E15 OVC 30 222/60/59/1608/019/ HIR CLDS VSB DSNT N-SE THN F ALQDS RE1205/ 8/6// 57018 60001 1 P.M. Weather: Overcast Stratus Temperature: 67F; Dew Point: 64F; Relative Humidity: 91% Wind: S at 9G15 kts Sea-level pressure: 30.14 ins. Hg: falling unsteadily Visibility: 20 miles, thin fog 6-hr Max temp: 67F 6-hr Min temp: 58F 6-hr Precip: 0.01 ins. BHO SA 1755 E13 OVC 20 205/67/64/1809G15/014/ THN F ALQDS/ 8/6// 58017 60018 10067 20058 SUMMARY FOR THURSDAY, JULY 16, 2020 TEMPERATURE (DEGREES F) MAX.....73   NORMAL.....81 MIN.....57   NORMAL.....63 MEAN....65   NORMAL.....72 DEPARTURE FROM 30-YEAR NORMAL................. -7 TOTAL DEPARTURE FOR THE MONTH.................+12 [+0.6 DEGREES/DAY] COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY................. 0  DEPARTURE...... -7 TOTAL COOLING UNITS FOR THE MONTH................115  DEPARTURE....... +8 TOTAL COOLING UNITS FOR THE SEASON...............299  DEPARTURE.......+63 TOTAL COOLING UNITS LAST SEASON TO DATE..........253  DEPARTURE.......+46 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................21 E   AT  3:29 P.M.                      AERO.........................21 E   AT  3:43 P.M.                     ASOS.........................20 ESE AT  5:36 P.M.                    DAVIS........................19 E   AT  3:29 P.M RMY 19 FASTEST MILE FOR YESTERDAY......................13 ESE AT  5:22 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................15 ESE AT  5:21 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................15 ESE AT  5:21 P.M. AVERAGE WIND SPEED AND DIRECTION.............. 7.3 ENE                               ASOS....................... 7.4                    DAVIS...................... 7.9 ESE [109 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.18  DEPARTURE......+0.04                          ASOS..............0.18 TOTAL PRECIPITATION FOR THE MONTH..........1.05  DEPARTURE......-0.88                          ASOS..............1.04 TOTAL PRECIPITATION FOR THE YEAR..........28.40  DEPARTURE......-0.50                          ASOS.............29.05 PRELIMINARY CLIMATE SUMMARY FOR JUNE 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 06/01  64/42/53/-9/T/0.0/724/80            28 WNW  AERO 29 WNW RMY 28 06/02  72/45/59/-3/0.01/0.0/689/76         28 W    AERO 27 W   RMY 28 06/03  79/55/67/+5/0.00/0.0/400/44         29 W    AERO 28 W   RMY 26 06/04  87/62/75/+12/0.00/0.0/673/74        26 W    AERO 25 S   RMY N/A 06/05  80/65/73/+10/0.14/0.0/300/33        28 SSW  AERO 28 SSW RMY N/A TSTM 06/06  86/57/72/+9/1.14/0.0/301/33         55 SW   AERO 59 SW  RMY 59  TSTM 06/07  68/54/61/-3/0.00/0.0/255/28         24 NW   AERO 24 NW  RMY N/A 06/08  77/51/64/0/0.00/0.0/866/95          25 W    AERO 24 W   RMY 25 06/09  77/60/69/+5/T/0.0/110/12            23 E    AERO 21 E   RMY N/A 06/10  70/58/64/-1/0.00/0.0/658/72         25 E    AERO 24 E   RMY N/A 06/11  71/64/68/+3/0.62/0.0/165/18         40 S    AERO 40 S   RMY 42 06/12  82/63/73/+8/0.00/0.0/705/77         26 W    AERO 25 W   RMY 27 06/13  71/53/62/-3/0.00/0.0/669/73         21 WNW  AERO 20 WNW RMY N/A             06/14  67/49/58/-8/0.00/0.0/852/93         21 E    AERO 21 ENE RMY 21 06/15  67/53/60/-6/5/0.00/0.0/696/76       21 NE   AERO 16 ENE RMY 20 06/16  73/54/64/-2/0.00/0.0/889/97         18 E    AERO 18 E   RMY 18 06/17  78/57/68/+1/0.00/0.0/889/97         20 S    AERO 20 S   RMY 20 06/18  86/59/73/+6/0.00/0.0/715/78         22 S    AERO 22 SSW RMY 22 06/19  86/66/76/+9/0.00/0.0/789/86         22 S    AERO 22 S   RMY 21 06/20  90/65/78/+10/0.00/0.0/834/91        22 S    AERO 21 S   RMY 21 06/21  90/66/78/+10/0.83/0.0/514/56        33 ESE  AERO 35 ESE RMY 33  TSTM 06/22  77/65/71/+3/T/0.0/761/83            15 E    AERO 17 S   RMY 14 06/23  85/65/75/+7/0.00/0.0/431/47         27 S    AERO 24 S   RMY 26 06/24  84/66/75/+6/0.00/0.0/348/38         25 S    AERO 24 S   RMY 25 06/25  84/63/74/+5/0.00/0.0/806/88         29 W    AERO 29 W   RMY 29 06/26  83/65/74/+5/0.02/0.0/769/84         25 S    AERO 25 S   RMY 27 06/27  82/65/74/+5/0.05/0.0/330/36         21 S    AERO 20 S   RMY 20 06/28  84/62/73/+3/3.27/0.0/421/46         35 W    AERO 33 N   RMY 37  TSTM 06/29  71/61/66/-4/1.46/0.0/064/07         18 NE   AERO 18 NE  RMY 18  TSTM 06/30  68/62/65/-5/0.02/0.0/027/03         14 ENE  AERO 14 ENE RMY 13 Record rainfall on the 28th of 3.27". Old record 2.09" in 1938 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/.../..             20 ENE  AERO 16 NNE RMY 18 07/07  78/60/69/-2/0.00/.../..             25 S    AERO 25 S   RMY 26 07/08  83/64/74/+2/0.00/.../..             32 SSW  AERO 32 SSW RMY 32 07/09  89/70/80/+8/0.00/.../.              24 S    AERO 23 S   RMY 22 07/10  83/70/77/+5/0.05/.../..             30 SSE  AERO 32 SSE RMY N/A 07/11  85/70/78/+6/0.00/.../..             39 S    AERO 39 S   RMY 38 07/12  86/70/78/+6/0.00/.../..             28 WSW  AERO 28 WSW RMY 29 07/13  82/69/76/+4/0.23/.../..             30 SSE  AERO 31 SSE RMY 30  TSTM 07/14  78/63/71/-1/0.00/.../..             26 ENE  AERO 25 ENE RMY 26   07/15  72/59/66/-6/0.00/.../..             21 NE   AERO 21 NE  RMY N/A 07/16  73/57/65/-7/0.00/.../..             21 E    AERO 21 E   RMY 19 07/17 The low since midnight is 57F, 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 17 HIGH 96F IN 1999 LOW 47F IN 1892 PRECIP 1.39 INS IN 1989 WIND 46 MPH WNW IN 1971 RECORDS FOR JULY 18 HIGH 96F IN 1991, 1999 LOW 54F IN 1892, 1956, 1971 PRECIP 1.65 INS IN 2000 WIND 43e MPH SW IN 1949 TODAY'S REPORT PREPARED BY: Andrew Swanson