The December heatwave scorched Canterbury today where the mercury hit 35C at Hanmer and Christchurch was not far behind on 33C this afternoon.

"Today is exceptionally hot and may well be record challenging/breaking with so many places in the mid 30s," said WeatherWatch.

While coastal areas are hovering just shy of 30C, inland weather stations are reporting temperatures as extreme as 38C, with many in the mid 30s, said WeatherWatch.

It said the heatwave continues in some New Zealand regions for the third or fourth week. Tomorrow, Dunedin is forecast to hit 29C.

On the other side of the world, London is sitting on 3C but it feels like -1C and it's a cool 5C in New York.

The heat is forecast to continue through the weekend and into Monday, but next week WeatherWatch is telling people to get ready for a "dramatic cool down".

"Daytime highs may be over 20 degrees lower than today with highs of just 16 to 18 degrees expected. For some, that may be the best forecast they've had in weeks!"

Here are the MetService forecasts around the country for tomorrow:
Whangarei - sunny with some cloud. High 24C. Overnight 16C.
Auckland - sunny with some cloud. High 24C. Overnight 17C
Hamilton - sunny with some cloud. High 25C Overnight 15C
Tauranga - sunny with a chance of showers. High 23C Overnight 17C
Wellington - sunny with some cloud. High 21C Overnight 17C
Christchurch - sunny with some cloud. High 31C Overnight 17C
Dunedin - sunny with a chance of rain. High 29C Overnight 14
Queenstown - rain. High 24C overnight 11C