Bay of Plenty 'heat swell' triggers MetService alert but cooler days to come

The New Year has delivered sunshine and sweltering heat for the Bay of Plenty, however, a thunderstorm watch is in place for the region today.

According to MetService, in Tauranga the temperature is expected to reach 28C today. On Wednesday the city's hottest reading was 30C.

Today, Rotorua is expected to reach a top temperature of 27C. Yesterday, the city experienced a high of 30C.

A thunderstorm watch is in place for Bay of Plenty, Rotorua and Coromandel until 9pm today.

Scorching temperatures were predicted for New Zealand this month but the nation hasn't experienced the worst, yet.

MetService meteorologist Kyle Lee said while humidity contributed to how hot people have felt, temperatures had not reached a record high for January.

Holidaymakers enjoy Mount Maunganui Beach on New Year's day when temperatures hit 30C. Photo / George Novak

According to Lee, Tauranga's record high for January is 33C, a temperature reached in 1983. Tauranga's average temperature for this month is 24.3C.

Rotorua's average January temperature is 22.9C, making 30C "quite high" in terms of its average, according to Lee.

"It's not really close to anything extreme yet, not quite tracking for record temperatures."

Lee said there had been a "heat swell" during the past few days.

MetService's new heat alert system was triggered in Rotorua and Tauranga this week.

The system measured daytime temperatures, humidity and the number of consecutive days heat is felt, in comparison to historical data.

The heat alert meant MetService would remind residents in areas affected by extreme temperatures that getting too hot can be dangerous.

Temperatures in Rotorua reached a high of 30C on Wednesday. Photo / NZME

"New Zealand is very changeable because it's a narrow strip of land in a large body of water," Lee said.

"We rely on systems. At the moment we are in a La Nina phase and we are expecting high pressure to dominate. It means there is clearer sky and less wind."

Lee said the high-pressure system affecting the country over the last few days came on the heels of a low-pressure system that brought in the humid air.

"Basically [the humidity] hasn't been able to go anywhere."

Lee said the heat would ease later today.

"Over the next few days, we will have a strong southerly coming through which will cool things down."

Niwa meteorologist Chris Brandolino said the weather has been "unusually warm".

"As a whole 2021 was exceptionally warm. It will probably finish as one of the top three on our records."

Niwa's latest climate summary reported last November to be the hottest in New Zealand's history.

Brandolino said last December was the hottest on record for Rotorua and Tauranga.

Niwa's records for Rotorua begin in 1964, while Tauranga's date back to 1913.

New Zealand is set for a scorching start to the year. Photo / NZME

Keeping yourself and others safe in hot weather:

• Drink plenty of water - try to drink two litres per day

• Stay out of the sun

• Have plenty of cold drinks

• If you need to be in the heat, stay in the shade where possible

• Avoid drinking alcohol, caffeine, and hot drinks

• Use sunscreen

• Eat nourishing food with a high water content (such as salads and fruit)

• Wear a hat

• Dress yourself and children in light clothing, cool cottons and natural fabrics are best

• Avoid extreme physical exertion

• People and pets should not be left in stationary vehicles

• Take a cool shower or bath

• Check in on others, especially those at most risk, children, elderly or those with health issues

• Spray or sprinkle water over skin or clothing, a damp cloth on the back of the neck can help

Source: MetService