Spring's mixed bag is set to continue for the South this week, with severe gales possible tomorrow and temperatures in the mid-20s followed by a cool end to the week.
Temperatures are expected to peak tomorrow in the South, but along with high temperatures the MetService has issued a severe weather outlook with heavy rain and severe gales possible across parts of the South.
There was a low chance of severe gales in Otago and Southland.
Heavy rain was also likely in other parts of the South Island, including the West Coast and the Otago and Canterbury headwaters.
There was also a moderate chance of severe gales in Canterbury and parts of the lower North Island.
Meanwhile, in the South Island Christchurch would crack 26C on Wednesday and Dunedin 24C.
Coming behind the northwest flow would be a cooler southerly change.
Both Christchurch and Dunedin are expected to drop to 12C on Friday. Oamaru is expected to drop to 10C and temperatures are expected to drop across the rest of the South Island.
In the North Island temperatures are forecast to approach a scorching 30C for some this week.
MetService meteorologist Tom Adams said a "good recipe" for hot temperatures was developing.
"We have a fairly moist air mass coming from the northwest, and northwest winds giving a bit of a foehn effect across the ranges."
The foehn effect occurred where an air mass released its moisture and produced heat as it passed over an area, leaving behind warm and dry air.
"So we have got a lot of rain falling in the mountains and are left with this very dry and warm wind."
The hottest temperatures would hit the South Island's east coast on Wednesday and the North Island's east coast Thursday.
Today was forecast to be mostly fine across the country, with a warm northerly flow and temperatures around 20C up and down both islands.
The hottest spots for the week were looking to be Hastings and Napier on Thursday, with forecasted highs of 29C and 28C respectively.
Southerlies would make their way up the country late Thursday into Friday, with some heavy rain in western areas.
By Saturday the southerly flow would have covered most of the country bringing cooler temperatures and showers to many areas.
By Sunday it was likely to settle for another nice day for most places.
Today's weather
Whangārei
Fine apart from evening cloud. Light winds. 22C high, 10C overnight.
Auckland
Fine for most, morning shower west coast. Southwest breezes. 20C high, 11C overnight.
Hamilton
Mainly fine, some morning and evening cloud. Light winds. 21C high, 7C overnight.
Tauranga
Fine. Northerly breezes in the afternoon. 22C high, 10C overnight.
New Plymouth
Fine apart from morning and evening cloud. Westerly breeze. 18C high, 12C overnight.
Napier
Fine. Light winds and afternoon sea breezes. 21C high, 10C overnight.
Whanganui
Fine apart from morning and evening cloud. Northwest breeze. 20C high, 11C overnight.
Wellington
Fine, then cloudy periods increasing. Northerlies strengthening. 17C high, 13C overnight.
Nelson
Fine. Light winds and afternoon sea breezes. 19C high, 10C overnight.
Christchurch
Fine. Northeasterlies developing in the afternoon. 21C high, 9C overnight.
Dunedin
A fine day, then some evening high cloud. Northerlies. 19C high, 12C overnight.
