August 2016 Summary – Warmest on Record
Blue Hill Observatory
August 2016 Summary:
The month continued the recent pattern of very warm, dry and sunnier than average weather. The 24-hour mean temperature for the month of 74.1 deg F was 6.0 degrees warmer than the 120-year average for August and nearly five degrees warmer than the 1981-2010 30-year average. August was the warmest on record and surpassed the previous record of 72.6 deg F in 2012 by one and a half degrees. The average maximum temperature for the month of 85.1 deg F surpassed the previous record for August of 83.2 deg F in 2005, and the average minimum temperature of 65.0 deg F also set a new record for the month surpassing 64.9 deg F in 2001. Despite the warmth, only two daily high minimum temperature records were set: 73F on the 11th and 74F on the 12th. The highest temperature for the month was 95F on the 12th, and the low temperature of 54F occurred on the 23rd. A total of 20 days had a high temperature of 85F or more, which was the most ever recorded in August surpassing the previous record of 16 in August 1988. There were 318 cooling degree days during August, which was also a new record for the month and 132 more than average. August brought only 1.78 inches of precipitation, which was more than two inches less than the long-term 120-year average and the 30-year mean. The greatest amount in 24 hours was 0.56 inches on the 13th-14th, which were also the only two days with thunderstorms during the month. The mean wind speed was 10.8 mph, with a prevailing direction from the south-southwest, and the peak gust was 40 mph from the south-southwest on the 14th. August sunshine was well above average with 70 percent of the possible bright sunshine being observed, which was 12 percent more than the long-term average, and this made August the seventh sunniest on record.
BHO Warmest August 24-hour Mean Temperature, deg F (1885-2016):
1) 74.1 in 2016
2) 72.6 in 2012
3) 72.5 in 1988
4) 72.4 in 2015
5) 72.3 in 2005
6) 72.1 in 2002
BHO Warmest August Average Maximum Temperature, deg F (1885-2016):
1) 85.1 in 2016
2) 83.2 in 2005
3) 83.1 in 1949
4) 82.6 in 2015
5) 82.5 in 1988
82.5 in 2002
82.5 in 2012
BHO Warmest August Average Minimum Temperature, deg F (1885-2016):
1) 65.0 in 2016
2) 64.9 in 2001
3) 64.6 in 2012
4) 64.4 in 2005
64.4 in 2015
BHO Greatest Number August Cooling Degree Days, (1885-2016):
1) 318 in 2016
2) 289 in 1988
3) 277 in 2002
4) 274 in 2005
5) 273 in 2012
6) 272 in 2015
BHO Sunniest Augusts, hours (1886-2016):
1) 303.7 in 1971 [74%]
2) 303.2 in 2015 [73%]
3) 303.0 in 1969 [73%]
4) 298.1 in 1932 [72%]
5) 296.7 in 1970 [72%]
6) 296.6 in 1995 [72%]
7) 291.0 in 2016 [70%]
8) 287.3 in 2014 [70%]
Summer (June-August) 2016 Summary:
The summer season was consistently very warm, dry and very sunny, and it was the warmest, the third driest and the second sunniest summer on record. The 24-hour mean temperature for June-August of 71.6 deg F was 4.3 degrees warmer than the 120-year average for summer and three degrees warmer than the 1981-2010 30-year average. Summer precipitation amounted to only 4.90 inches, which was about 6.5 inches less than the long-term mean and nearly 7.5 inches less than the 30-year normal. This was the lowest summer rainfall total since 1957, and at the end of August much of eastern Massachusetts was in an extreme drought. There was 68 percent of the possible bright sunshine during the summer, and the total of 888.2 hours of sunshine during June-August was the second highest ever measured behind only 919.7 hours in summer 1971.
BHO Warmest Summers (Jun-Aug), deg F (1885-2016):
1) 71.6 in 2016
2) 71.3 in 2010
3) 70.8 in 1949
4) 70.6 in 1999
5) 70.4 in 1952
6) 70.2 in 2005
BHO Driest Summers (Jun-Aug), inches (1885-2016):
1) 3.48 in 1949
2) 3.54 in 1957
3) 4.90 in 2016
4) 5.24 in 1965
5) 5.43 in 1964
6) 5.45 in 1997
BHO Sunniest Summers (Jun-Aug), hours (1886-2016):
1) 919.7 in 1971 [71%]
2) 888.2 in 2016 [68%]
3) 876.0 in 1965 [68%]
4) 863.8 in 1966 [67%]
5) 862.5 in 2014 [66%]
Mike Iacono
Chief Scientist
Blue Hill Observatory
