Weather Eye with John Maunder

Temperatures have been recorded in the Tauranga area at several sites over the last 100 years including the current Tauranga Airport site from June 1990.

It is very common for areas such as Tauranga to have had different observation sites over the years and the readings from the earlier sites have been adjusted to the present site using "standard climatologically procedures".

It is considered that the temperature series described here is a fair and true record of what the temperature would have been if the current observation site (Tauranga Airport) had been used throughout the period.

It is important to note, that 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 are those for the average daily maximum temperatures. Later analyses will be for the average daily minimum temperatures.

The graph shows details of the average daily maximum temperatures (called simply "afternoon" from now on), for Tauranga for March from 1913-2012.

Note that March 1947 is not included because of incomplete data. The long-term average afternoon temperature in March Tauranga for is 22.5 degrees C, ranging from the "cool" March months of 1960 with an average afternoon temperature of 20.4 degrees C , and 1940 with an average afternoon temperature of 20.8 degrees C, to the "warm" March months of 1916 (24.7 degrees C), and 1938 and 1968 (24.6 degrees C).

The graph of the average afternoon temperatures for March shows generally "normal" variations from March to March with the earlier years of the record (1913, 1914, 1916), and the late 1990's (1998,1999, 2002), being notably "warmer" than other March months.

From 1914 to 2012, there have been 13 March months with an average afternoon temperature of 23.6 degrees or more, and 11 years with an average afternoon temperature of 21.0 degrees or less.

The value for March 2013 was 24.1 degrees which shows that it was the fifth equal warmest March month since records began in 1913.

The 10 "warmest" March months ( in terms of afternoon temperatures) on record, in chronological order, are 1913, 1916, 1938,1948,1955,1968,1990, 2005, 2010 and 2013. In contrast the 10 "coolest" March months (in terms of afternoon temperatures) on record, in chronological order, are 1923,1934,1936,1940,1945,1949,1960,1974,1992, and 1998.

The average afternoon temperature For March for the 48 years from 1914-1962 was 22.4 degrees C, compared with an average of 22.6 degrees for the 48 years from 1963-2011.

This small warming over the last 96 years is similar to warming in the months of January, February, April, May, June, July and August , compared with slight cooling in the months of September, October, November and December.

For further information Google 'Dr John Maunder” or https://sites.google.com/site/climaterisksandbenefits/.