Temperatures were also slightly above usual, despite the cold snap which hit the country late in the month.
The average temperature in Tauranga in June was up 0.4C to 11.4C.
Some forecasters predicted there could be a dusting of snow on the Kaimai Ranges about June 20 as a cold snap swept through the country.
While that did not eventuate, the same front saw the Desert Rd and Mt Ruapehu get a heavy dump. Daytime highs sat at about 12C, while overnight lows dropped to about 3C during that week.
Tauranga's weather during the autumn months of March, April and May was the wettest, warmest and sunniest of the main centres.
Niwa National Climate Centre's seasonal climate summary stated that autumn had been 29 per cent wetter than normal, with 423mm of rain falling in Tauranga.
On April 20, State Highway 2 was closed by flooding near Waihi. Waihi Beach Rd was also impassable.
Visitors had to be evacuated from two camping grounds, with people being rescued from cars caught by floods and slips.
Surface flooding affected parts of Tauranga and properties were also flooded in Katikati, Omokoroa, Mount Maunganui and Te Puke. Local roads throughout the Western Bay were affected and power was lost to homes in Otumoetai after a slip damaged a transformer.
But an average mean air temperature of 17C - 1.3C above normal - made it the warmest autumn since local records began in 1913.
Tauranga's warmest autumnal day, equalling its second highest ever, was 30C on March 1. On the same day, Te Puke registered its highest temperature in 40 years of records, with 30.1C.