with John Maunder
The May rainfall in Tauranga in 2017 was 154 mm.
Apart from the exceptional rainfall of 634 mm in May 2005, the graph shows a small decrease in overall May rainfalls when two recent adjacent 50-year periods are compared.
Since 1898, there have been 14 May months with a rainfall of 200 mm or more. In chronological order, the wettest May months are: 1899, 1900, 1917, 1925, 1926, 1928, 1949, 1950, 1956, 1961, 1962, 1971, 2005, and 2010.
In terms of dry May months, there have been only nine May months with a rainfall of less than 40 mm.
In chronological order, the driest May months are: 1901, 1918, 1939, 1941, 1978, 1991, 1999, 2007, and 2014. Of particular significance is the exceptional rainfall in May 2005.
I estimated that such a rainfall is likely to occur in Tauranga only about twice in every 1000 years.
This suggests central government could have had a much more important role in the financial implications of the floods, which affected many areas of Tauranga in May 2005 that occurred.
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