BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA FRIDAY, OCTOBER 9 2020 ALL TIMES ARE IN EASTERN STANDARD TIME A DAZZLING FALL DAY ATOP GREAT BLUE HILL... Clear skies, light winds, and temperatures in the upper-30s were found here upon our arrival. The low bottomed out at 37 degrees marking the coldest air of the season. The last time the temperature reached 37 or below was back on May 13th...149 days or just under 5 months ago! Visibility has been astounding - horizon to horizon - averaging 85 miles throughout the day. Fall colors are also becoming more visible around us. The Neponset River Valley is exhibiting the most advanced and vibrant colors thanks to its low-lying elevation allowing for superb radiational cooling on clear, calm nights. The high so far today is 57, 6 degrees below the daily normal of 63F. The low since midnight is 48F, which is 2 degrees above the normal low of 45F. PRELIMINARY STATS FOR SEPTEMBER 2020 TEMPERATURE, Deg. F Avg. Max. 73.2 [+1.6] Avg. Min. 54.9 [+0.3] Mean      64.1 [+1.0] 24-hour corrected mean: 63.6 Max. for month: 82F on the 8th Min. for month: 39F on the 22nd HEATING DEGREE DAYS Total heating units:    95 [-22] Total for the season:   98 [-44] Total for last season:  93 COOLING DEGREE DAYS Total cooling units:     73  [+13] Total for the season:   830  [+233] Total for last season:  680 PRECIPITATION, Inches Total: 1.61 [-2.45] Greatest in 24 hrs: 1.02 ins. on 29th-30th WIND, mph Avg. uncorrected wind speed: 10.6 mph Avg. corrected wind speed:   11.1 mph Prevailing wind direction:   S [20%] Peak gust and direction:     71 S on the 30th SUNSHINE: Campbell-Stokes card minutes: 12150 minutes of a possible 21582 or 56% Astronomical total minutes: 12593 minutes of a possible 22403 or 56% Today's Observations: 7 A.M. Weather: Clear (few cumulus E & S; few altocumulus SSW-WSW) Temperature: 40F; Dew Point: 30F; Relative Humidity: 68% Wind: NW at 9 kts Sea-level pressure: 30.21 ins. Hg: rising, then rising more rapidly Visibility: 85 miles 6-hr Max temp: 42F 6-hr Min temp: 37F 24-hr Precip: 0.00 ins. BHO SA 1155 CLR 85 231/40/30/3209/021/ FEW CU DSNT E AND S FEW AC DSNT SSW-WSW/ 8/150 53025 10042 20037 10 A.M. Weather: Clear Temperature: 52F; Dew Point: 21F; Relative Humidity: 29% Wind: NNW at 9G13 kts Sea-level pressure: 30.24 ins. Hg: rising, then rising more slowly Visibility: 85 miles 3-hr Precip: 0.00 ins. BHO SA 1455 CLR 85 240/52/21/3309G13/024/ 8/000 51009 1 P.M. Weather: Clear (few cumulus S-SW; few cirrus S-SW) Temperature: 56F; Dew Point: 25F; Relative Humidity: 29% Wind: WNW at 9G16 kts Sea-level pressure: 30.18 ins. Hg: falling, then falling more rapidly Visibility: 85 miles 6-hr Max temp: 57F 6-hr Min temp: 40F 6-hr Precip: 0.00 ins. BHO SA 1755 CLR 85 219/56/25/2909G16/018/ FEW CU DSNT S-SW FEW CI DSNT S-SW 8/101 58021 10057 20040 SUMMARY FOR THURSDAY, OCTOBER 8, 2020 TEMPERATURE (DEGREES F) MAX.....61   NORMAL.....63 MIN.....42   NORMAL.....46 MEAN....52   NORMAL.....54 DEPARTURE FROM 30-YEAR NORMAL.................-2 TOTAL DEPARTURE FOR THE MONTH................+17 [+1.9 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY.............13  DEPARTURE......+2 TOTAL HEATING UNITS FOR THE MONTH.............58  DEPARTURE.....-19 TOTAL HEATING UNITS FOR THE SEASON...........156  DEPARTURE.....-64 TOTAL HEATING UNITS LAST SEASON TO DATE......169  DEPARTURE.....-13 COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY............. 0  DEPARTURE.......0                   TOTAL COOLING UNITS FOR THE MONTH..............1  DEPARTURE..... -2 TOTAL COOLING UNITS FOR THE SEASON...........831  DEPARTURE....+231 TOTAL COOLING UNITS LAST SEASON TO DATE......682  DEPARTURE....+149 PEAK WIND GUST FOR YESTERDAY (MPH)                    420C/Official................41 W  AT  12:06 A.M.                      AERO.........................41 W  AT  12:02 A.M.                    ASOS.........................40 W  AT  12:06 A.M.                    DAVIS........................42 W  AT  12:05 A.M.                    RMY N/A  MERLIN N/A FASTEST MILE FOR YESTERDAY......................28 W  AT  12:07 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................29 W  AT  12:07 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................31 W  AT  12:07 A.M. AVERAGE WIND SPEED AND DIRECTION.............15.7 WNW (376 total miles)                            ASOS......................15.1                    DAVIS.....................15.9 WNW [299 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE....-0.14                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.16  DEPARTURE....-1.03                          ASOS..............0.12 TOTAL PRECIPITATION FOR THE YEAR..........34.58  DEPARTURE....-5.69                          ASOS.............35.33 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  76/59/68/0/0.00/698/88              22 SSE  AERO 21 SE   RMY 20 09/02  69/59/64/-4/0.18/102/13             23 SSE  AERO 23 SSE  RMY 24 09/03  75/66/71/+4/0.04/000/00             22 SSW  AERO 21 SSW  RMY N/A 09/04  82/62/72/+5/0.00/763/98             26 WNW  AERO 26 WNW  RMY 25 09/05  76/55/66/-1/0.00/760/98             25 W    AERO 25 W    RMY 24 09/06  78/58/68/+1/0.00/356/46             24 W    AERO 24 W    RMY N/A 09/07  79/61/70/+4/0.00/632/82             27 SSE  AERO 30 SSE  RMY 28 09/08  82/61/72/+6/0.00/545/71             17 S    AERO 16 S    RMY 17 09/09  80/62/71/+5/0.00/214/28             16 S    AERO 15 S    RMY 16 09/10  81/69/75/+10/0.28/015/02            21 SSW  AERO 21 SSW  RMY N/A 09/11  72/55/64/-1/0.01/152/20             25 N    AERO 25 N    RMY N/A 09/12  68/51/60/-5/0.00/666/88             21 ENE  AERO 21 ENE  RMY 21 09/13  74/53/64/0/0.00/611/81              26 SSW  AERO 26 SSW  RMY 26 09/14  74/50/62/-2/0.00/511/68             29 NNW  AERO 33 NNW  RMY 30 09/15  64/44/54/-10/0.00/583/78            18 S    AERO 18 S    RMY N/A 09/16  72/49/61/-2/0.00/603/81             31 SSW  AERO 31 SSW  RMY 31 09/17  76/57/67/+4/0.00/453/61             26 WSW  AERO 28 W    RMY N/A 09/18  64/48/56/-6/0.00/163/22             28 NE   AERO 30 NNW  RMY N/A 09/19  59/42/51/-11/0.00/722/98            23 N    AERO 23 N    RMY N/A 09/20  58/40/49/-13/0.00/602/82            25 NE   AERO 25 NE   RMY 27 09/21  61/41/51/-10/0.00/694/95            29 NE   AERO 27 NE   RMY 29 09/22  63/39/51/-10/0.00/022/03            28 NNW  AERO 30 NNW  RMY 29 09/23  78/50/64/+4/0.00/617/85             31 NW   AERO 32 WNW  RMY 32 09/24  76/57/67/+7/0.00/347/48             20 SW   AERO 18 WSW  RMY 19 09/25  77/57/67/+7/0.00/655/91             18 ENE  AERO 18 WSW  RMY N/A 09/26  77/57/67/+8/0.00/516/72             21 S    AERO 21 S    RMY 21 09/27  79/64/72/+13/0.01/121/17            24 S    AERO 25 S    RMY 24 09/28  78/64/71/+13/0.07/199/28            24 SSE  AERO 24 S    RMY 25 09/29  76/62/69/+11/0.01/234/33            30 S    AERO 30 S    RMY N/A 09/30  72/56/64/+6/1.01/395/56             71 S    AERO 88 S    RMY N/A PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 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 10/01  75/56/66/+9/0.00/.../..             28 SW   AERO 28 SW   RMY N/A 10/02  63/49/56/-1/0.02/.../..             20 NW   AERO 21 NW   RMY 20 10/03  65/45/55/-1/0.00/.../..             19 WNW  AERO 19 WNW  RMY 19 10/04  65/45/55/-1/0.00/.../..             17 ESE  AERO 18 ESE  RMY 18 10/05  62/52/57/+1/0.00/.../..             17 ENE  AERO 17 ENE  RMY N/A 10/06  69/51/60/+5/0.00/.../..             28 S    AERO 28 S    RMY 29 10/07  73/50/62/+7/0.14/.../..             76 W    AERO 74 W    RMY 70 10/08  61/42/52/-2/0.00/.../..             41 W    AERO 41 W    RMY N/A 10/09  The low since midnight is 37F, the daily normal low is 45F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):   RECORDS FOR OCTOBER 9 HIGH 82F IN 2011 LOW 29F IN 1907,1937 PRECIP 2.54 INCHES IN 1976 SNOWFALL 0.2 INCHES IN 1888 PEAK GUST 81e MPH S IN 1976 (RECORD FOR MONTH) RECORDS FOR OCTOBER 10 HIGH 85F IN 1949 LOW 27F IN 1929 PRECIP 2.02 INCHES IN 1998 SNOWFALL 6.8 INCHES IN 1979 (RECORD FOR MONTH) PEAK GUST 59 MPH WNW IN 1958 TODAY'S REPORT PREPARED BY: Andrew Swanson