with John Maunder
The graph below shows the range of Tauranga's October rainfalls, from an extreme high of 357 mm in 1916 to a low of only 7 mm in 1984.
The second wettest October was 1928, when 269 mm was recorded; and the second driest October was in 1928, when only 11 mm fell.
The long-term average rainfall for Tauranga in the month of October is 110 mm.
The rainfall in October 2017 was 162 mm.
The graph of the October rainfall shows at first glance normal variations from year to year.
However, there has been a notable decrease in the October rainfalls during most the last Octobers.
Indeed, the average October rainfall in Tauranga during the 50-year period from 1961-2010 of 88 mm, is only 70 per cent of the rainfall for the 50-year period 1910-1960.
Since 1898, there have been 11 October months with a rainfall of 200 mm or more (10 of which occurred during the period 1900-1958), and only one October month since then has recorded this much. Ten October months have also experienced rainfalls of 25 mm or less.
In chronological order the eleven wettest October months are 1900, 1905, 1916, 1918, 1921, 1926, 1928, 1941, 1952, 1958, and 1983. In contrast the eleventh driest October months are 1906, 1938, 1963, 1965, 1969, 1973, 1984, 1993, 2010, 2013, and 2015.