As I alluded to earlier last month, this past summer was on track to be one of the hottest on record. Well, after a very warm August, the final numbers are in… And 2016 did indeed take home the #1 spot in Cleveland with a mean temperature of 75.5F. According to my expanded dataset, the top ten hottest summers (1855-present) are as follows:
- 2016 75.5F
- 1949 75.0F
- 1995 74.9F
- 2010 74.4F
- 1955 74.4F
- 2005 74.3F
- 2012 73.9F
- 1952 73.9F
- 1944 73.5F
- 2011 73.3F
Figure 1: Chart showing annual mean summertime temperatures (June 1-August 31) as recorded in Cleveland, Ohio for the period 1855 to the present.
In addition, many other locations in the region with log periods of record also recorded record (or near record) warmth this past summer.
At Akron/Canton, this was the hottest summer on record with a mean temperature of 74.2F. The previous record was 73.8F, set in 1991 and 1931. Records for the Akron/Canton region date to 1887. From 1887 to 1932, records were kept at the University of Akron, from 1932 to 1948 at present-day Akron Fulton International Airport, and since 1948 at Akron/Canton Regional Airport in Green Township, Ohio. Note: the earlier stations were lower in elevation and more urbanized in character, and probably would tend to run a little warmer. Akron Fulton International Airport tends to run from 1-1.5F warmer than Akron/Canton Regional Airport, and had a mean temperature of 75.7F this summer.
In the Mansfield area, this summer tied for second hottest on record with a mean temperature of 73.7F. The record is 74.0F, set in 1934. The summer of 1995 also had a mean temperature of 73.7F, similar to this year. Records in the Mansfield area date to 1917. The official records for Mansfield were taken at the co-operative site 5 miles west of town until 1948, and again from 1956-1959. The remaining records were taken at the Mansfield Lahm Municipal Airport.
At Detroit, Michigan, this was the hottest summer on record with a mean temperature of 74.9F, narrowly edging out 2005 (74.8F) and 2012 (74.7F). Records date to 1874.
At Flint, Michigan, this was the third hottest summer on record with a mean temperature of 73.7F. The hottest summer on record was in 1933 with a mean temperature of 74.2F, followed by 1934 at 74.0F. Records date to 1893.
At Lansing, Michigan, this was the fifth hottest summer on record with a mean temperature of 72.0F (tying both 1949 and 1921). 1955 holds the record with a mean temperature of 73.6F, followed by 2005 (72.8F), 2012 (72.6F), and 2010 (72.4F). Records date all the way back to 1863.
At Pittsburgh, PA, this was the eighth hottest summer with a mean temperature of 74.4F. The record is 75.8F from 1900. However, due to a number of factors (elevation, urbanization, latitude), the old records taken downtown tend to run from 2 to 4 degrees warmer than comparable airport records (Allegheny County Airport and Pittsburgh International Airport), effectively eliminating the entire warming trend (which is on the order of 1.5F or so). This results in the majority of heat records being from the late 1800s and early 1900s, despite the fact that this period tended to be considerably cooler than the present. Since airport records began in 1935 (Alleghency County Airport in West Mifflin, from 1935 to 1952, and Pittsburgh International Airport in Moon Twp. from 1952 to the present), only one summer was hotter – namely, 1995 with a mean temperature of 75.1F.
At Erie, PA, this was the fourth hottest summer on record with a mean temperature of 72.7F. Only 1949 (73.7F), 2005 (73.2F), and 1995 (72.8F) were warmer. Records at Erie, PA date to 1871.
At Buffalo, New York, this was the third hottest summer on record with a mean temperature of 73.5F. Only 2005 (73.1F) and 1949 (72.7F) were warmer. Records at Buffalo date to 1874.
And at Rochester, New York, this was the second hottest summer on record with a mean temperature of 72.8F. Only 1949 (73.0F) was warmer.
The story was pretty similar for much of the south and east, where numerous locations saw a top five hottest summer (with several locations recording their hottest summer yet). It was a little cooler further west, but still well above normal. Milwaukee had its fifth hottest summer with a mean temperature of 73.1F, trailing only 2012 (74.1F), 1995 (73.8F), 1988 (73.8F), and 2010 (73.2F). Records at Milwaukee date to 1871. I suspect when all is said and done that this will be the hottest summer on record nationally, finally eclipsing the long-held standard from 1934. Some recent summers came close – most notably, 2012 and 2006, but couldn’t quite unseat the top summer.
In any event, it is clear that warming climate is beginning to manifest itself in the records. In most of the locations given above (with records dating to the mid- to late 1800s), this decade alone has seen four of the top 10-15 hottest summers on record (2010, 2011, 2012, and now 2016). The current warm period is challenging, and beating out, a prior warm period from the 1930s-1950s.
Also of note, the Great Lake water temperatures resumed their warming trend (after a couple of relatively cooler years in 2014 and 2015). At Buffalo, NY, where water temperatures have been taken continuously since 1926 near the municipal intake at a depth of 30-35′, this was only the fourth year ever in which the water temperature reached or exceeded 79F. The water temperature reached 79F+ from August 13-19, 1988 (peaking at 80F on the 14th through 16th), again on August 2, 2006 (79F), and on several days in late July/early August in 2011 (peaking at 80F on two days). This summer, the water temperature there peaked at 79F on the 13th and 14th, but remains elevated. The current reading of 76F is one shy of the record from 1959.