July 2016 Summary – Tied for Fifth Warmest on Record

Blue Hill Observatory
July 2016 Summary:

The month was notable for being very warm, dry and sunnier than average. The 24-hour mean temperature for the month of 74.0 deg F was 4.3 degrees warmer than the 120-year average for July and more than three degrees warmer than the 1981-2010 30-year average. The highest temperature for the month was 96F on the 22nd and 25th, and the low temperature of 56F occurred on the 10th and 11th. The high of 96F on the 25th was a new daily maximum temperature record for the date, surpassing 94F set previously in 1963 and 1987. A stretch of seven consecutive days with a maximum temperature of 90F or higher occurred on the 22nd through 28th, and this was the third longest heat wave on record for any month and the longest ever observed in July. A total of 11 days had a high temperature of 90F or more, which was the second most ever recorded in July behind only 14 in July 1952.  The average maximum temperature during the month of 84.7 deg F was the fifth warmest on record for July. There were 10 heating degree days during July, which is one more than average, and the total cooling degree days was 317, which was 95 more than average. July brought only 1.50 inches of precipitation, which was about two inches less than the long-term 120-year average and about two a half inches less than the 30-year mean. The combined June-July precipitation of 3.12 inches was the sixth lowest on record for those two months. The annual total rainfall through July of 23.19 inches represents only 75% of the normal precipitation for the first seven months of the year, and the continued dry weather has left parts of eastern New England in a severe drought. The greatest amount in 24 hours in July, 0.56 inches, fell on the 30th-31st. There were four days with thunderstorms, which is one less than average, and the annual total is now up to 11. The mean wind speed was 10.7 mph, with a prevailing direction from the west, and the peak gust was 45 mph from the north-northwest on the 23rd. July sunshine was well above average with 66 percent of the possible bright sunshine being observed, which was 8 percent more than the long-term average. The combined June-July bright sunshine of 597.2 hours, or 68 percent, was the seventh highest on record.

BHO Warmest July Mean Temperature, deg F (1885-2016):

1) 75.1 in 2010
2) 74.9 in 1952
3) 74.1 in 1994
    74.1 in 2013
5) 74.0 in 2011
    74.0 in 2016
7) 73.8 in 1999
8) 73.5 in 1949
9) 73.2 in 2012

BHO Warmest July Average Maximum Temperature, deg F (1885-2016):

1) 87.2 in 1952
2) 86.5 in 2010
3) 85.5 in 1949
4) 84.9 in 1994
5) 84.7 in 2016
6) 84.5 in 1911
7) 84.4 in 1983

BHO Longest Heat Waves (Consecutive Days with Tmax 90F or more; 1885-2016):

1) 9 days, Aug 11-19, 2002
2) 8 days, Aug 10-17, 1944
3) 7 days, Jul 22-28, 2016
4) 6 days, Aug 28-Sep 2, 1953
    6 days, Jul 24-29, 1963
    6 days, Jul 16-21, 1977
    6 days, Jul 6-11, 1988
    6 days, Jul 16-21, 1991
    6 days, Jul 15-20, 2013
10) 5 days, Jul 2-6, 1911
    5 days, Jul 7-11, 1912
    5 days, Aug 25-29, 1948
    5 days, Aug 7-11, 1949
    5 days, Jul 15-19, 1982
    5 days, Jul 14-18, 2012

BHO July Greatest Number of 90-Degree Days (1885-2016):

1) 14 in 1952
2) 11 in 2016
3) 10 in 1949
    10 in 1963
    10 in 2010
    10 in 2013
7) 9 in 1911
8) 8 in 1983
    8 in 1988

BHO Driest June-July, inches (1885-2016):

1) 1.91 in 1957
2) 1.97 in 1949
3) 2.38 in 1983
4) 2.51 in 1997
5) 2.85 in 1994
6) 3.12 in 2016
7) 3.27 in 1888
8) 3.40 in 1890

BHO Sunniest June-July, hours (1886-2016):

1) 616.4 in 1971 [70%] 2) 615.5 in 1952 [70%] 3) 611.1 in 1908 [69%] 4) 608.5 in 1965 [69%] 5) 600.3 in 1953 [68%] 6) 598.7 in 1899 [68%] 7) 597.2 in 2016 [68%]
8) 595.1 in 1909 [67%]

Mike Iacono
Chief Scientist
Blue Hill Observatory