with John Maunder
The graph below shows details of the average daily maximum temperatures, called ‘afternoon', for Tauranga for July from 1913-2019. The temperature for July 2019 was 15.8 degrees Celsius.
It's very common for areas such as Tauranga to have had different observation sites during the years, and readings from the earlier sites have been adjusted to the present site using standard climatologically procedures.The temperature series described here is a record of what the temperature would have been if the current observation site, Tauranga Airport, had been used throughout the period.
It's important to note, in considering climate change, the methodology used in computing an official set of climate observations is very important as otherwise erroneous conclusions may be drawn.
Traditionally, temperature observations have been recorded with a set of maximum and minimum temperature thermometers.
These record the daily maximum temperature, usually recorded in mid-afternoon, and daily minimum temperature, usually recorded just before dawn.
This analysis of temperatures for Tauranga is for average daily maximum temperatures.
The long-term average afternoon temperature in July for Tauranga is 14.1 degrees Celsius, ranging from cool July months of 1918 and 1939, both 12.3 degrees Celsius, and 1965, with 12.9 degrees Celsius, to the mild July months of 1916, 2010, and 2019 both 15.8 degrees Celsius, and 1915 with 15.7 degrees Celsius.
The graph of the average afternoon temperatures for July shows generally normal variations from July to July in the last 100 years.
But several July months since 1997 have been a little warmer than many of the July months since 1913.
From 1913 to 2019, there have been seven July months with an average afternoon temperature of 15.2 degrees Celsius or more, and 11 July months with an average afternoon temperature of less than 13.3 degrees Celsius.
The seventh mildest July months for afternoon temperatures on record, in chronological order are: 1915, 1916, 1917, 1984, 1998, 2000, and 2019.
By contrast, the seven coolest July months for afternoon temperatures on record, in chronological order are: 1918, 1929, 1935, 1939, 1963, 1965, and 1969.
The average afternoon temperature for Tauranga for July for 49 years from 1914-1962 was 14.0 degrees Celsius, compared with the average afternoon temperature for Tauranga for July for 49 years from 1963-2011 was 14.2 degrees Celsius.
For further information on a range of weather and climate matters see: https://sites.google.com/images/climatediceandthebutterfly/