Weather Eye with John Maunder

The graph below shows the range of Tauranga's December rainfalls, from an extreme high of 447 mm in 1962 to a low of only 4 mm in 1930.

The second wettest December was 2011, when 276mm was recorded; and the second driest December was in 1994, when only 14mm fell.

The long-term average rainfall for Tauranga for December is 100mm. The rainfall for December 2014 was 145 mm.

The graph of the December rainfall shows, at first glance, normal variations from year to year.

However, there has been a notable increase in December rainfalls during the last few decades. Indeed, the average December rainfall in Tauranga for the 50-year period from 1961-2010 of 109mm, is 20 per cent higher than the rainfall for the 50-year period 1911-1960.

Since 1898, there have been eight Decembers with a rainfall of 200mm or more, five of which occurred during the period 1962 to 2011.

Seven December months have experienced rainfalls of 30mm or less. Of significance are the high rainfalls in the consecutive December months of 1962 and 1963, of 447mm and 224mm respectively.

In chronological order, the eighth-wettest Decembers are 1924 with 225mm, 1928 with 227mm, 1936 with 240mm, 1962 with 447mm, 1963 with 224mm, 1996 with 241mm, 2001 with 208mm and 2011 with 276mm.

In contrast, the seventh-driest December months in chronological order are 1902 with 27mm, 1912 with 22mm, 1919 with 22mm, 1930 with 4mm, 1986 with 30mm, 1990 with 21mm and 1994 with 14mm.

For further information on a variety of climate matters see: https://sites.google.com/site/climatediceandthebutterfly/