Heavy rain warning as winter kicks in

Heavy rain is heading to Rotorua

May's weather statistics were on par with previous years and a "fair indication" winter has arrived, Rotorua's resident weatherman says.

Despite a relatively warm start to the month, with temperatures sitting around the high teens, May's weather wrap up suggests that from here on locals will be needing those extra layers.

Yesterday, a severe weather warning was issued by MetService, saying a complex trough would be bringing heavy rain to much of central New Zealand, including Rotorua and the wider Bay of Plenty.

The Bay of Plenty and the area north of Gisborne could see up to 120mm accumulated in 12-18 hours, especially about the hills and ranges of Bay of Plenty.

People are advised this rain could make driving conditions hazardous, cause rivers and streams to rise rapidly and lead to surface flooding and slips.

Springfield-based weatherman Brian Holden said the average temperatures, rainfall and number of frosts for May were about the same as in previous years. The warmest day, May 6, reached a balmy 21C but the two coldest nights, at the end of the month, dropped to an icy -1.2C.

From May 28-31 there were four frosts - the only frosts Rotorua experienced throughout the month.

There was a total of 120.1mm of rain, of which 49.5mm fell on May 23. This was slightly less than the Rotorua rainfall norm of 145mm for the month.

"You can see the temperature steadily dropping throughout the month and ending with four negative-degree mornings and frosts."

Mr Holden said while winter officially started yesterday, in his experience, the weather often showed signs of change during May.

According to MetService, tomorrow will see occasional showers and by Thursday those are expected to gradually ease.