‘Sharp change’ in temperatures coming, some places plunging by as much as 15C

Niwa’s forecast temperature map for 6am on Friday.
Cooler temperatures are coming after an early summer scorcher swept the east coast of New Zealand.
Forecaster Niwa said a “brief but sharp change” was predicted for Friday, with a possibility that some locations could be 10C to 15C cooler in the space of 24 hours.
MetService says a southerly change is bringing cooler conditions after Christchurch sizzled at 30C-plus on Thursday.
Timaru may struggle to reach the mid-teens on Friday, with a high of only 16C forecast.
A front moves on to the North Island early on Friday, spreading a band of scattered rain and cooler temperatures as far north as Rotorua, before stalling.
MetService meteorologist Ngaire Wotherspoon said rain from the “weakened front” would stick around over the North Island this weekend before clearing on Sunday night.
“Down south the weekend is looking sunnier, with temperatures starting to warm up again on Sunday as we head into summer,” Wotherspoon said.
Summer to spring in 24 hours.Eastern parts of both islands will near or exceed 30°C today. 🥵However, a brief (but sharp) change is on the way.Comparing forecast temperatures at 2 pm today with 2 pm tomorrow, some locations will be 10-15°+ cooler.🎢 pic.twitter.com/6S6Pf8vBKB
Niwa said the cool change comes after New Zealand saw its first 30C temperature of the spring on Thursday – recording a maximum temperature of 33.3C in Riccarton, Christchurch. It said this was the warmest spring day for the suburb since 2002.
Niwa said the sweltering temperatures were credited to a “warm air mass and gusty westerly winds”.
Other areas in the Canterbury region that surpassed 30C included Bromley, Christchurch Gardens and Rangiora.
In the North Island, Niwa also recorded Waiora in the Hawke’s Bay as reaching 31.3C.
Niwa reports temperatures are likely to be warmer than average through to January, with frequent northwesterly winds leading to more days above 25C.
Also raising the odds for hot summer weather was the potential for marine heatwave conditions – already occurring in seas to the east of New Zealand – to expand and intensify.
While warmer seas might sound welcome to beachgoers, marine heatwaves have helped drive glacier melts, extreme deluges – and a cascade of damaging impacts beneath the surface.
And dry and hot conditions are already fuelling concern about fire danger, months away from the peak of summer.
Fire and Emergency New Zealand Hawke’s Bay district manager Glen Varcoe confirmed fire-risk indices were late last week elevated to high across the Ahuriri and Heretaunga districts, including Napier and Hastings and coastal regions north to Wairoa.
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