Many parts of New Zealand are in for an "absolute scorcher" this weekend, a meteorologist says – and drought-hit areas will likely have to go another week before there's any chance of relief.
Niwa forecaster Ben Noll said the latest maps showed how those pockets of the North Island under meteorological drought, stretching from eastern Auckland to Northland, were expanding daily under the continuing dry spell.
"And the hottest days of summer are still coming, from Friday, over the weekend, and into next week," he said.
Eastern parts of the South Island, particularly, could see temperatures soaring past 35C on Saturday.
"I wouldn't be surprised if some places get to feel the effects of 37C. And that's preceded by another scorcher for Southland, Otago and interior parts of the South Island on Friday."
The effect of heat in those driest areas would be compounded by the fact there was little moisture in the ground for the sun to evaporate – meaning its radiative force would be felt much more strongly.
"These places will have a week of this to contend with, and each day will be pretty darn warm," he said.
"We are keeping an eye on a low that may approach the North Island later next week, and put an end to the hot spell and bring rain, but it's still a little early to go into that."
While the Ministry for Primary Industries hadn't yet classified any region as experiencing an "adverse event", it was monitoring the situation closely, a spokesperson said.
"MPI is communicating regularly with the local Rural Support Trusts and local advisers, who are in touch with the sector representatives and farmers in the affected areas."
The forecast came as many councils had been forced to bring in water restrictions in many regions.
At Auckland's dams, total water storage levels were sitting at 77 per cent.
"While we are keeping a close eye on this, it is not a cause of concern at this stage," Watercare spokeswoman Rachel Hughes said.
"To ensure we preserve the water stored in our large dams in the Hunua Ranges, we are maximising production at our Waikato, Onehunga and Huia water treatment plants when possible."
Next month, Watercare is kicking off a new campaign to encourage people to think about their water use and to reduce the volume of water being wasted.
"This will include information to educate people about 'peak' demand – people use a lot more water on hot days which causes peaks in demand."
Water restrictions around NZ
NORTHLAND/KAIPARA: No hoses or sprinklers allowed in Opononi/Omapere, Kaitaia, Kaikohe/Ngawha, Kawakawa/Moerewa, Dargaville and Ruawai. No sprinklers allowed in Omanaia/Rawene, Kerikeri/Waipapa, Waitangi/Paihia/Opua and Okaihau. Residents urged to use water sensibly elsewhere.
AUCKLAND: No current restrictions in place.
COROMANDEL/HAURAKI: Total watering ban in Coromandel Town, Hahei, Whitianga, Waihi and Waikino; alternate days' use in Whangamata and Matarangi; residents in Tairua, Pauanui and Onemana, and across Hauraki District asked to conserve water.
BAY OF PLENTY/TAUPO: No current restrictions in Tauranga, Western Bay of Plenty, Whakatane, Kawerau, Rotorua, Opotiki. Sprinklers and watering systems banned in Kinloch, garden watering allowed only on alternate days elsewhere in Taupo district.
WAIKATO/WAITOMO: Sprinklers only allowed on alternate days in Hamilton, Tauwhare, Matangi, Gordonton, Morrinsville and Te Aroha, and Mokau in Waitomo. Sprinkler use in Pirongia, Te Awamutu and residents on the Pukerimu Scheme only allowed between 6am to 8am and 6pm to 8pm. Matamata, Te Kuiti, Piopio and Benneydale residents asked to conserve water.
HAWKE'S BAY AND GISBORNE: Alternate day sprinkler and hose use restrictions in Napier and Hastings, between 6am to 8am and 7pm to 9pm. Hose use allowed before 10am and after 4pm in Central Hawke's Bay on alternate days; sprinkler use prohibited and washing of vehicles and buildings permitted only with a bucket and sponge. No current restrictions in Wairoa or Gisborne.
TARANAKI: Sprinklers, irrigation systems and unattended hoses banned in New Plymouth until end of March; hand-held hoses allowed on alternate days. No restrictions in place in Stratford or South Taranaki.
WHANGANUI/MANAWATU/TARARUA: Total hose ban in Akitio and Norsewood. Alternate day restrictions in Dannevirke, Eketahuna, Pahiatua, Woodville and Pongaroa. Marton residents asked to continue conserving water due to damage to the spillway of the Marton raw water supply dam. No restrictions in Whanganui, Ruapehu, Manawatu, Palmerston North.
WAIRARAPA: Sprinklers allowed on alternate days in Masterton and South Wairarapa. Hand-held hoses allowed in Carterton on alternate days.
LOWER NORTH ISLAND: Hoses and sprinklers allowed on alternate days from 5am to 7am and from 7pm to 9pm on alternate days in Horowhenua. Sprinklers and hoses allowed from 6am to 8am and 7pm to 9pm in Hutt City, Upper Hutt, Porirua and Wellington. No restriction in Kapiti.
TASMAN/MARLBOROUGH: No restrictions in Tasman, Marlborough and Nelson City.
EASTERN SOUTH ISLAND: Permanent hose ban in Ashburton district at Dromore, Methven Springfield and Montalto, no "non-essential" water use allowed at Mt Somers. Sprinklers and irrigation systems banned for residents using the Waipara and Hawarden-Waikari water supplies in Hurunui district. Sprinklers and hoses allowed for two hours maximum per day in Twizel. No restrictions in Kaikoura, Christchurch, Waimakariri, Timaru and Waimate and Waitaki.
WEST COAST: Residents on Westport/Carters Beach water supply asked to restrict the amount of water they use each day. No restrictions in Grey or Westland districts.
OTAGO AND SOUTHLAND: Temporary conserve water notice for Alexandra. Sprinklers in Clutha district only allowed from 8pm to 8am. No restrictions in place in Gore, Dunedin, Queenstown Lakes district, Southland and Invercargill.