July 2022 Summary – Warmest Month on Record

Blue Hill Observatory July 2022 Summary: 

July was exceedingly warm with much less rainfall and much more sunshine than expected. The approximated 24-hour mean temperature for the month of 75.3 deg F was 5.3 degree warmer than the 1891-2020 130-year average for July, and it was 3.6 degrees warmer than the 1991-2020 30-year average. July 2022 was both the warmest July on record and the warmest month ever observed at Blue Hill. The average maximum temperature of 86.6 deg F was 4.9 degrees warmer than the 30-year normal, and it was the second warmest on record for July. The average minimum temperature of 65.7 deg F was 1.9 degrees warmer than the 30-year normal, and it was the fourth warmest on record. The warmth peaked during a six-day heat wave on July 19th-24th that ended with the highest temperature for the month of 99F on the 24th, which surpassed the previous record for the date of 96F set in 1987. This reading was the highest temperature at Blue Hill since 99F was observed on July 22, 2011. This heat wave was one of the ten longest ever recorded at Blue Hill since 1885. There were eight 90-degree days during July, which tied for the eighth most for the month. The heat was made even worse by the very limited rainfall during the month, which continued a long stretch of dry months and pushed the area into severe drought. The total precipitation was only 0.80 inches, which was 2.67 inches less than the 30-year normal. The greatest rainfall in 24 hours was only 0.25 inches during a thunderstorm on the 2nd. For the five months from March to July, the total precipitation was just 11.05 inches, which was about half of the 30-year average rainfall, and this total was the 3rd driest on record for these five months. There was two thunderstorm days during July on the 2nd and the 17th, which was three fewer than average for the month. The mean wind speed for July was 11.2 mph, and the prevailing wind direction was from the south-southwest. The highest wind gust was 39 mph from the south-southwest on the 21st and southwest on the 24th. July sunshine was much above average with 322.6 hours, or 73 percent of the possible bright sunshine, which was 15 percent more than the long-term average, making July the third sunniest on record.

BHO Highest Monthly 24-Hour Adjusted Mean Temperature, deg F (1885-2022):

1) 75.3 in July 2022
2) 75.1 in July 2010
3) 74.9 in July 1952
4) 74.5 in July 2019
5) 74.1 in July 1994
   74.1 in July 2013
   74.1 in August 2016
8) 74.0 in July 2011
   74.0 in July 2016

BHO Highest July 24-Hour Adjusted Mean Temperature, deg F (1885-2022):

1) 75.3 in 2022
2) 75.1 in 2010
3) 74.9 in 1952
4) 74.5 in 2019
5) 74.1 in 1994
   74.1 in 2013
7) 74.0 in 2011
    74.0 in 2016
9) 73.8 in 1999
10)73.6 in 2018
   73.6 in 2020

BHO Highest July Average Maximum Temperature, deg F (1885-2022):

1) 87.2 in 1952
2) 86.6 in 2022
3) 86.5 in 2010
4) 85.5 in 1949
5) 84.9 in 1994
6) 84.7 in 2016
7) 84.6 in 1911
   84.6 in 2019
9) 84.4 in 1983
10)84.3 in 1999

BHO Highest July Average Minimum Temperature, deg F (1885-2022):

1) 66.9 in 2013
2) 66.0 in 2020
3) 65.9 in 2010
4) 65.7 in 2022
5) 65.6 in 1994
   65.6 in 2019
7) 65.3 in 2006
8) 65.1 in 2008
9) 64.9 in 1999
10)64.7 in 1955
   64.7 in 2018

BHO Longest Heat Waves (1885-2022):

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
   6 days, Jul 19-24, 2022

BHO Highest Daily Maximum Temperatures, deg F (1885-2022):

1) 101 on Aug 10, 1949
   101 on Aug 2, 1975
3) 100 on Aug 9, 1949
   100 on Jul 21, 1977
5) 99 on Jul 3, 1911
   99 on Jul 10, 1911
   99 on Jun 4, 1919
   99 on Jul 22, 1926
   99 on Aug 12, 1944
   99 on Aug 27, 1948
   99 on Jul 30, 1949
   99 on Jul 23, 1952
   99 on Sep 2, 1953
   99 on Jul 20, 1991
   99 on Aug 14, 2002
   99 on Jul 6, 2010
   99 on Jul 22, 2011
   99 on Jul 24, 2022

BHO Highest July Number of 90-Degree Days (1885-2022):

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
   8 in 2022

BHO Lowest July Precipitation, inches (1885-2022):

1) 0.13 in 1953
2) 0.33 in 1957
3) 0.72 in 1968
4) 0.80 in 2022
5) 0.85 in 1917
6) 0.87 in 1937
7) 0.92 in 1965
8) 1.08 in 1939

BHO Fewest July Days With Measurable Precipitation (1885-2022):

1) 5 in 1980
2) 6 in 1897
3) 7 in 1924
   7 in 1955
   7 in 1961
   7 in 2016
   7 in 2022

BHO Highest July Sunshine, hours (1886-2022):

1) 331.6 in 1952  [75%]  
2) 326.4 in 1966  [73%]  
3) 322.6 in 2022  [73%]  
4) 317.3 in 1899  [71%]  
5) 317.0 in 1909  [71%]  
6) 316.4 in 2001  [71%]  
7) 314.0 in 1893  [71%]  
8) 313.6 in 1968  [71%]  

Mike Iacono
Chief Scientist
Blue Hill Observatory