Scorching temperatures, showers for most regions today

Rainy weather hasn't been stopping Aucklanders from getting into the summer spirit, this bunch jumping from the Murrays Bay Wharf last week. Photo / Greg Bowker

The heat is on over most regions today, but warm temperatures will be paired with widespread rain to kick the week off.

Most spots around the North Island would peak at around 24C, with Masterton scooping the hottest high of 28C.

Further down the country, Cantabrians could also expect searing temperatures. Christchurch was expected to reach 27C.

MetService was forecasting "occasional rain" over the North Island, with showers expected to become heavy in some regions including New Plymouth.

MetService had issued a weather watch for heavy rain for the northern and western North Island.

The watch affected the Taranaki area, where rain accumulation was expected to approach warning criteria.

Showers were expected at some point today for all regions over the South Island, with the exception of Christchurch.

The warm temperatures expected over the country followed a hot night in many regions.

Tauranga had already reached 21.6C by 6am and was sitting at 21C around 2am.

In Auckland, temperatures were likewise sitting around 21C at 2am.

This was 5C higher than the 16C overnight average for January.

Temperatures over the South Island hovered around 18C overnight.

Weather Watch said the next two days would bring unusually humid, damp and cloudy weather across the North Island.

Many regions would see heavier downpours on Tuesday and isolated thunderstorms in some spots across the island.

The wet weather would disappear by late on Tuesday in most regions to make way for some sunshine towards the end of the week.

As we head into February, we'll be keeping close tabs on the Tasman & Coral Seas as warmer-than-average conditions combined with favorable Madden-Julian Oscillation phase(s) could result in a rather wet month for NZ 💦 pic.twitter.com/vp7b85rulb

— NIWA Weather (@NiwaWeather) January 19, 2018

The scorching hot start to the week followed the news January could be shaping up to the hottest in New Zealand's recorded history.

Climate scientist Jim Salinger told the Herald if the average temperature for the month slides up only half a degree, it may be the hottest month since records first began.

The average January temperature is 17.1C, the average so far for January 2018 was 19.3C - the hottest since records began in 1909.

Salinger had downloaded the climate data from Niwa's seven stations which were used to calculate New Zealand's average temperature.

The stations are located at Auckland Airport, Kelburn in Wellington, Masterton Airport, Hokitika Airport, Nelson, Lincoln near Christchurch and Musselburgh, Dunedin.

With 10 days left in January the average temperature was unlikely to drop given there were no "cool southerlies in the weather projections".

The warmer-than-usual temperatures were being attributed to a "marine heatwave" unfolding across the Tasman Sea and in New Zealand coastal waters.

Some waters near New Zealand remained 5C above average.

February, like January, could be the warmest on record.

If that was the case then it was possible that this summer would be the hottest in recorded history, Salinger said.