A heat alert has been issued for Napier as the mercury rises above 30C, while the top of the country is cloaked in humid air.
It comes after international and domestic flights were delayed this morning after fog settled over Auckland Airport.
Napier is currently the hottest place in the country, sitting at 31C. Gisborne closely follows on 30C.
Other extremes include Whangārei, Christchurch and Timaru on 27C.
MetService meteorologist John Law said Auckland temperatures were expected to soar to 29C today and not drop much lower as the day continued.
By 1pm the humidity in Auckland had reached 93%.
Law said temperatures were not expected to drop by much for the rest of the day, only falling to 21C overnight.
What a difference a day can make.
— NIWA Weather (@NiwaWeather) February 1, 2026
For the eastern South Island...
🥵 Today: Upper 20s to near 30°C
🥶 Tomorrow: May not reach 15°C
The temperature change will come with rain tonight & early tomorrow. Stay up-to-date with the forecast with @MetService. pic.twitter.com/ho705ekzgs
A heat alert has been issued for Napier, warning people to keep hydrated, seek shade and check vulnerable people, pets and livestock.
Law said the warm temperatures were the remains of a tropical system being dragged down from the north.
“It’s not as big as some of the systems we’ve seen, but it’s still bringing down that warmth and that moisture, leading to a really warm and humid start, which is also helping to form some of those misty, murky conditions around the coast as well.”
Monday's emojicast:
— NIWA Weather (@NiwaWeather) February 1, 2026
☁️
☁️
🌧️🌧️
🌧️🌧️☁️☁️
🌧️🌦🌧️🌤️
🌦🌧️🌤️
🌧️🌦
🌤️
🌤️☀️
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🌧️🌤️🌤️ 🌦
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A scattering of showers today is “something to look out for,” Law said.
Law said the heat would be more “seasonal” tomorrow, back down to the mid-20s for most places.
Meanwhile, a range of weather watches are in place for parts of the South Island.
A🟡Heavy Rain Watch🟡has been issued for Fiordland spanning the 16 hours from 11pm Sunday the 1st of February to 3pm Monday the 2nd of February.
— MetService NZ (@MetService) January 30, 2026
The forecast is for a period of heavy rain; where amounts may approach warning criteria, with a moderate chance of upgrading to a… pic.twitter.com/7s3T2DLBPJ
A heavy rain watch is in place for the ranges of Westland, south of Fox Glacier, until 9pm today and Fiordland until 3pm.
The same watch will be in place for Marlborough south of Seddon and Canterbury north of the Rangitata River from 2am tomorrow until 10pm.
A strong wind watch has been issued for the Westland and Grey Districts and Fiordland from early tomorrow morning.
An airport spokesperson said six regional flights and two Australian flights, one heading to Sydney and another arriving from Melbourne, were delayed by the conditions.
The affected international flights were JQ202 to Sydney and JQ217 from Melbourne.
The fog restrictions were introduced at 5.50am and lifted at 6.55am.