BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, JANUARY 6, 2016 ALL TIMES ARE IN EASTERN STANDARD TIME TEMPERATURES BEGIN TO MODERATE AFTER ANOTHER CHILLY OVERNIGHT Yesterday's average temperature of 14F provided the coldest day of the winter thus far, with a temperature departure of 12 degrees below normal and a minimum temperature of 4F. Completely clear skies were present at this morning's 7:00 AM EST observation, with a thermal inversion present below the summit. By today's 1:00 PM EST observation skies remained clear with only a few thin cirrus fibratus distant to the S and WSW-NE. Temperatures had reached a maximum of 42F by that time as well. DECEMBER FINISHES AS THE WARMEST ON RECORD...NEARLY FIVE  DEGREES WARMER THAN PREVIOUS RECORD FOR THE MONTH... THIRD RECORD WARM MONTH IN 2015...GREATEST POSITIVE TEMPERATURE DEPARTURE FOR ANY MONTH...DECEMBER ALSO AMONG CLOUDIEST ON RECORD... BHO Warmest Decembers (24-hour Mean), deg F (1885-2015) 1) 42.9 in 2015 2) 38.1 in 2006 3) 37.5 in 2011 4) 37.3 in 2001 5) 37.2 in 1891 6) 36.9 in 1998 7) 36.7 in 1990 BHO Largest Monthly 24-Hour Mean Temperature Departure from the Long-Term Mean, deg F (1885-2015): 1)+13.1 in December 2015 2) +9.9 in January 1913 3) +9.3 in January 1932 4) +9.1 in March 1946 5) +9.0 in March 2012 6) +8.9 in January 1937 7) +8.5 in February 1984 BHO Lowest December Sunshine, hours (1885-2015): 1) 72.9 in 1972  [27%] 2) 81.0 in 1982  [29%] 3) 87.2 in 1933  [32%] 4) 88.2 in 1996  [32%] 5) 89.0 in 1922  [32%] 6) 89.5 in 1981  [33%] 7) 91.1 in 1906  [33%] 8) 92.0 in 2012  [34%] 9) 92.9 in 2013  [34%] 10) 93.3 in 2015 [34%] PRELIMINARY STATS FOR DECEMBER 2015 TEMPERATURE, Deg. F Avg. Max. 50.5 [+11.4] Avg. Min. 36.9 [+13.3] Mean      43.7 [+12.4] 24-hour Corrected Mean: 42.9 [+13.1] Max. for month: 67 on 24th Min. for month: 23 on 29th, 30th HEATING DEGREE DAYS Total cooling units: 654 [-389]   Total for the season: 1656 [-649] Total for last season: 2060 PRECIPITATION, Inches Total: 4.27 [-0.49] Greatest in 24 hrs: N/A Snowfall: 1.3 [-12.1] Greatest in 24 hrs: 1.3 ins. on the 29th    WIND, mph Avg. uncorrected wind speed: 11.3 Avg. corrected wind speed: 11.8 Prevailing wind direction: W @ 12% Peak gust and direction: 48 W on the 15th SUNSHINE: Campbell-Stokes card minutes: 5598 mins. of possible 16470 or 34% Astronomical total minutes:   5786 mins. of possible 17002 or 34% Long-term average for December is 46% Today's Observations: 7 A.M. Weather: Sky clear Temperature: 21F; Dew Point: 0F; Wind: WSW at 11 kts Sea-level pressure: 30.51 ins. Hg, falling, then more slowly Visibility: 75 miles 6-hr Max temp: 22F  6-hr Min temp: 17F 24-hr precip: 0.00 ins. 24-hr snowfall: 0.0 ins. Snow depth: Trace BHO SA 1155 CLR 75 331/21/0/2511/051/ SKC INVSN PRSNT BLO SMT ESTMD TOP 2 HND FT/ 8/000 50000 10022 20017 10 A.M. Weather: Clear, few cirrus distant SW and WNW-NNE Temperature: 29F; Dew Point: 3F; Wind: SW at 8 kts Sea-level pressure: 30.51 ins. Hg, steady, then rising Visibility: 80 miles BHO SA 1455 CLR 80 333/29/3/2309/051/ FEW CI DSNT SW AND WNW-NNE/ 8/001 53002 1 P.M. Weather: Clear, few cirrus distant S and WSW-NE Temperature: 42F; Dew Point: -4F; Wind: SW at 11G18 kts Sea-level pressure: 30.44 ins. Hg, rising, then falling and lower  Visibility: 80 miles 6-hr Max temp: 42F 6-hr Min temp: 20F BHO SA 1755 CLR 80 308/42/-4/2311G18/044/ FEW CI DSNT S AND WSW-NE/ 8/001 58025 10042 20020 SUMMARY FOR TUESDAY, JANUARY 5, 2016     TEMPERATURE (DEGREES F) MAX.....23   NORMAL.....34 MIN......4   NORMAL.....18  MEAN....14   NORMAL.....26 DEPARTURE FROM 30-YEAR NORMAL......................-12 TOTAL DEPARTURE FOR THE MONTH.......................+1 [+0.0 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............51   DEPARTURE.........+12 TOTAL HEATING UNITS FOR THE MONTH.............192   DEPARTURE..........-1 TOTAL HEATING UNITS FOR THE SEASON...........1848   DEPARTURE........-649 TOTAL HEATING UNITS LAST SEASON TO DATE......2228   DIFFERENCE.......-380 PEAK GUST AND AVERAGE WIND SPEED (MPH)  PEAK WIND GUST FOR YESTERDAY...................28  NNW AT  1:31 A.M.*                    ASOS........................28  NNW AT  1:28 A.M.                    DAVIS.......................24  N   AT  1:38 A.M. RMY N/A FASTEST MILE FOR YESTERDAY.....................19  NNW AT  1:39 A.M.  MAXIMUM 2-MINUTE ASOS AVERAGE..................20  NNW AT  1:39 A.M.  MAXIMUM 2-MINUTE DAVIS AVERAGE.................17  NNW AT  1:39 A.M.  AVERAGE WIND SPEED AND DIRECTION.............11.0 N                    ASOS......................11.0                       DAVIS......................9.5 NNW [327 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.........TRACE  DEPARTURE......-0.72                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE YEAR..........TRACE  DEPARTURE......-0.72                            ASOS..............0.00 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.......-0.5 TOTAL SNOWFALL FOR THE MONTH................0.2  DEPARTURE.......-2.6 TOTAL SNOWFALL FOR THE SEASON...............1.5  DEPARTURE......-17.3 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER/JANUARY CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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 12/1  42/30/36/-1/0.16/0.0/000/00           19 NNE RMY 19 12/2  53/37/45/+9/0.20/0.0/000/00           25 SSE RMY 25 12/3  53/37/45/+9/0.01/0.0/162/29           43 WNW RMY 42 12/4  47/32/40/+5/0.00/0.0/444/80           32 NW  RMY 32 12/5  50/33/42/+7/0.00/0.0/548/99           21 W   RMY N/A 12/6  57/35/46/+11/0.00/0.0/531/96          22 SW  RMY N/A 12/7  54/37/46/+12/0.00/0.0/353/64          31 NE  RMY N/A 12/8  42/35/39/+5/0.01/0.0/000/00           32 NE  RMY 31 12/9  44/34/39/+5/0.00/0.0/044/08           28 SSE RMY N/A 12/10 57/41/49/+16/T/0.0/209/38             29 SE  RMY N/A 12/11 56/44/50/+17/0.00/0.0/049/09          28 SSW RMY 28 12/12 59/46/53/+20/0.00/0.0/367/67          23 W   RMY N/A  12/13 54/44/49/+17/0.00/0.0/000/00          18 ESE RMY 19 12/14 60/43/52/+20/0.45/0.0/000/00          32 S   RMY N/A 12/15 61/45/53/+21/0.17/0.0/371/68          48 W   RMY 51  12/16 45/34/40/+9/0.00/0.0/415/76           25 N   RMY N/A 12/17 53/36/45/+14/0.50/0.0/000/00          29 SE  RMY 28 12/18 50/35/43/+12/0.10/0.0/000/00          29 NW  RMY 30 12/19 38/30/34/+4/0.00/0.0/480/88           39 W   RMY 40 12/20 40/28/34/+4/0.00/0.0/491/90           24 W   RMY N/A 12/21 51/31/41/+11/T/0.0/000/00             38 SSW RMY 42 12/22 57/49/53/+24/0.28/0.0/000/00          35 SW  RMY 35 12/23 54/47/51/+22/0.61/0.0/000/00          30 E   RMY 27  12/24 67/48/58/+29/0.31/0.0/033/06          37 SSW RMY 39   12/25 64/52/58/+30/..../0.0/240/44          23 N   RMY N/A 12/26 53/40/47/+19/..../0.0/436/80          26 NNW RMY N/A 12/27 52/35/44/+16/..../0.0/000/00          36 NW  RMY 33 12/28 35/27/31/+3/T/T/355/65                33 NW  RMY 33 12/29 38/23/31/+4/..../1.3/000/00           35 ENE RMY 35 12/30 34/23/29/+2/..../T/000/00             17 SSE RMY N/A 12/31 44/32/38/+11/..../0.0/258/47          25 WNW RMY 25 1/1   37/29/33/+6/0.00/0.0/.../..           29 W   RMY 29 1/2   37/27/32/+5/0.00/0.0/.../..           31 W   RMY N/A          1/3   41/27/34/+8/0.00/0.0/.../..           28 W   RMY 29 1/4   30/10/20/-6/T/T/000/00                29 NNW RMY 29 1/5   23/4/14/-12/0.00/0.0/.../..           28 NNW RMY N/A 1/6 low since midnight is 17F; normal low is now 18F   DAILY RECORDS FOR DECEMBER 2015 **12/13/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 44F, BREAKS PREVIOUS RECORD OF 43F SET IN 1919, TIED 1983 **12/24/2015- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 67F, BREAKS PREVIOUS RECORD OF 61F SET IN 2014 **12/24/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 48F, BREAKS PREVIOUS RECORD OF 46F SET IN 1900 **12/25/2015- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 64F, BREAKS PREVIOUS RECORD OF 62F SET IN 1889 **12/25/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 52F, BREAKS PREVIOUS RECORD OF 46F SET IN 1964 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):  RECORDS FOR JANUARY 6 HIGH 66F IN 2007 LOW -14F IN 1896 PRECIP 3.10 INS. IN 1889 [RECORD FOR MONTH] SNOWFALL 7.5 INS. IN 1893 PEAK GUST 70 MPH WNW IN 1959 RECORDS FOR JANUARY 7 HIGH 60F IN 1930 LOW -7F IN 1896 PRECIP 1.97 INS. IN 1977 SNOWFALL 16.0 INS. IN 1977 PEAK GUST 74 MPH NW IN 1968 TODAY'S REPORT PREPARED BY: Brian Fitzgerald