Early spring temperatures have been near average, however MetService says temperatures have swung widely between much warmer and significantly colder periods in September.
Figures provided by local weatherman Brian Holden also show it's been more than a little wet. He had the annual rainfall to date at his Springfield weather station as 1872mm with the total yearly normal at 1587mm.
Mr Holden reports the September temperature was normal at 10.6C.
Niwa principal scientist of forecasting Chris Brandolino said temperatures for the next three months until December were forecast to be above average for Rotorua.
"There is a 60 per cent chance for above average temperatures however that does not mean every week from now until Christmas will be above average. There is still a chance frosts and cool snaps will occur in the period.
"However the nor'easterly winds that bring the warmer temperatures also bring with them moisture, so the chance of rain is elevated. Niwa is forecasting rainfall totals for the three-month period to be slightly (40 per cent) higher than average (35 per cent)."
He said coastal waters remained generally warmer than average all around the country.