with John Maunder
Temperatures have been recorded in the Tauranga area at several sites in the last 100 years, including the current Tauranga Airport site from June 1990.
The graph shows details of the average daily maximum temperatures (simply called “afternoon”) for Tauranga for September from 1913-2017.
The long-term average afternoon temperature in September for Tauranga is 16.6 degrees C, ranging from the “cool” September months of 1964 (14.8 degrees C), and 1977 (14.9 degrees C), to the “warm” September months of 1915 (18.4 degrees C), and 18.3 degrees in 1914.
The afternoon temperature for 2015 was 16.1 degrees C, which made it the coolest September for 11 years.
In contrast, September 2017 had an average afternoon temperature of 16.8 degrees C, which was close to normal.
The graph of the average afternoon temperatures for September shows generally "normal" variations from September to September during the last 100 years, but five of the warmest six September months occurred from 1913 to 1921.
From 1913 to 2017, there have been ten September months with an average afternoon temperature of 17.5 degrees C or more, and eight September months with an average afternoon temperature of less than 15.4 degrees C.
The tenth “warmest” September months (in terms of afternoon temperatures) on record, in chronological order, are 1913, 1914, 1915, 1916, 1921, 1926, 1940, 2006, 2009 and 2014.
By contrast, the eighth “coolest” September months (in terms of afternoon temperatures) on record, in chronological order, are 1935, 1964, 1967, 1977, 1992, 1993, 1994 and 1997.
The average afternoon temperature during September for the period 1914-62 was 16.6 degrees, compared with 16.5 degrees from 1963-2011.
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