Hot January for Whanganui - but not the hottest

Good weather for swimming, at Whanganui East Pool. Photo / File

Last month was the third warmest January in New Zealand since records began, Niwa climate scientist Nava Fedaeff says.

The average temperature nationwide was 18.8C - but not as high as the January 2018 average of 20.3C. Across the country temperatures were 0.5C to 1.2C - or more - warmer than average.

The hottest temperature recorded was in Hanmer Forest, near Christchurch, on January 31 - a time when parts of the country were experiencing a heat wave.

Both Nelson and Gisborne had record sunshine hours during the month.

The hot weather was caused by a series of high pressure systems. Adding to that were warmer than normal sea temperatures, with marine heatwaves in parts of the central and western Tasman Sea.

Hawera experienced its third highest average January air temperature - 18.2C. Waiouru had its third highest average too, 16.3C, and Ōhakune had its fourth highest - 17.2C.

Ōhakune and Waiouru also had their highest maximum recorded daily temperatures, with both on January 29. For Ōhakune it got to a scorching 31.1C, and in Waiouru the temperature topped 29.7C.

For the past two years there have been no record low temperatures set in New Zealand.

Rainfall was less than the January usual in most places - with the notable exceptions of Napier and Hastings in the North Island and Otago and Southland in the south.

Whanganui didn't break any records or have an official heatwave - but it had top temperatures of 26C-plus from January 27-30.

It was also windy here at times - but nowhere near the top wind gust recorded for the month. That was 182km/h, at Cape Turnagain on January 27.