KEY POINTS:
Hot weather blasted the country today with temperatures in Christchurch reaching 40 degrees Celsius.
Hotter than normal temperatures were widespread over New Zealand with 12 locations between Timaru and Gisborne recording temperatures of more than 30degC, MetService spokesman Bob McDavitt said.
Rain was pummelling Stewart Island and parts of Southland but the weather was fine from Queenstown north, he said.
The MetService had recorded air temperatures up to 35.7degC in Christchurch, which made it the hottest day of the summer so far and neared its January record high of 35.9degC in 1979.
However, Christchurch-based weather analyst Richard Green told the New Zealand Herald thermometers reached 40degC in the early afternoon with the suburb of Barrington reaching 41degC, Cashmere 40degC and Christchurch city 38degC.
Mr McDavitt said this hot air was part of the weather system that brought temperatures to over 40degC in Sydney recently.
"The air is 20 to 25 degrees coming off the Tasman Sea and warming by around 10 degrees when it crosses the Southern Alps and spreads over the Canterbury plains."
Temperatures near 30degC were forecast for Canterbury tomorrow, with a cooling southerly expected to arrive on Saturday.
Mr McDavitt advised people feeling stressed by the heat to drink more water, stay inside or go for a swim.
Police tonight urged motorists on the Desert Road to exercise caution due the extreme heat causing the tar seal on the road to melt and lift.
A spokeswoman said sand had been put down on the road but this has also made conditions slippery.
Signs has been placed in the affected areas.
The warm weather came on the same day as the National Institute of Water and Atmospheric Research (Niwa) forecast above average temperatures across New Zealand through to March.
NIWA said it was likely to be drier than average in the south, but rainfall in the north was expected to be normal or above normal.
Niwa predicted more easterlies than normal in the north but lighter winds than normal in the south.
Moderate La Nina conditions were likely to continue into autumn, it said.
There was a slightly higher chance of an ex-tropical cyclone passing within 500km of the country during the cyclone season through to May.
- NZ HERALD STAFF, NZPA
