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 2018, when 278 mm was recorded

The second driest December was in 1994, when only 14 mm fell.

The rainfall for December 2021 was 116 mm.

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

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

However, there has been an 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 109 mm, is 20 percent higher than the rainfall for the 50-year period 1911-1960. In contrast, four recent December months (2015, 2016, 2017, 2020) have had low rainfalls of 18 mm, 44 mm, 29 mm and 19mm.

Since 1898, there have been nine Decembers with a rainfall of 200 mm or more, six of which occurred during the period 1962 to 2018. Nine December months have experienced rainfalls of 30 mm or less. Of significance are the high rainfalls in the consecutive December months of 1962 and 1963, of 447 mm and 224 mm respectively.

In chronological order, the nine-wettest Decembers are 1924 with 225 mm, 1928 with 227 mm, 1936 with 240 mm, 1962 with 447 mm, 1963 with 224 mm, 1996 with 241 mm, 2001 with 208 mm, 2011 with 276 mm, and 2018 with 278 mm.

In contrast, the ninth-driest December months in chronological order are 1902 with 27 mm, 1912 with 22 mm, 1919 with 22 mm, 1930 with 4 mm, 1986 with 30 mm, 1990 with 21 mm, 1994 with 14 mm, 2015 with 18 mm, and 2020 with 19 mm.

For further information on a range of weather/climate matters see:

Fifteen shades of climate By John Maunder ... My new book ......

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The idea for the book came about when I was visiting my family in Adelaide in January 2020 during a heat wave. One day when the forecast was for 45°C my daughter Denise suggested I should stay inside, shelter from the heat and write another book. I asked what did she have in mind and she simply said Climate the Truth. My son Philip who has lived in Adelaide for about 30 years thought it was a good idea but after a few days thought I settled on a more appropriate title Fifteen shades of climate... the fall of the weather dice and the butterfly effect.

The book is now available through the web site amazon.com. Just Google 'fifteen shades of climate” for details.

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