A change in wind direction will mean Northlanders get "a bit of a break" from the scorching heat that saw the mercury in the Whangārei area creeping towards 40C.
The city recorded 32.8C on Monday - the warmest temperature on record according to NIWA records - but MetService's weather station in Whau Valley was showing a reading of 37.4C at 3pm yesterday.
Kerikeri is another Northland town that's breaking weather records, with the mercury of 33.2C on Saturday being the second warmest after 34.3C was recorded in January 1960.
Niwa meteorologist Ben Noll said the Whangārei area was feeling the heat as the district was more landlocked and experienced more westerlies than places such as Dargaville, Kerikeri and Kaitaia, which were closer to the coast.
"But there's quite a cool change coming to Northland from Wednesday with a change in the wind direction from the westerlies to southerlies and that will continue through the weekend.
"The temperatures will come down about 5C or so and people will notice a drop in humidity which will make sleeping easier. But it will get quite warm from the second half of next week.
"Summer may be taking a bit of a break but it's not signing off just as yet," Noll said.
• Warmth and humidity will make sleeping difficult in Northland
• Premium - Summer-like feel in Northland and more humidity on the way
• Fans flying off Northland store shelves as many have to work in humidity
All areas in Northland have received less than 15mm of rain in January.
The highest temperature recorded in Northland was 35C at Waipoua Forest on January 30, 1991, and the lowest -5.6C at Glenbervie Forest on July 31, 1957.
These compare with national extremes of 42.4°C and -25.6°C.
Road construction workers are among those feeling the brunt of searing temperatures.
Kia Tupato Security had to pull out a male and female employee from the Tarewa Rd roadworks on Monday after both became a "bit unsteady" on their feet due to the hot weather, company director Wayne Stokes said.
"We've had to buy extra shade hats to go with the helmet, ice blocks, and making sure we have plenty of fluids. Our people have felt a bit light headed on occasions so they get a bit of an easier day."
United Civil Construction group manager health, safety, quality and environmental strategies Paul Bonetti said the company has adopted a number of measures to ensure workers were not affected by the sizzling heat.
"We prioritise scheduling work outside the higher daytime temperatures. For example, one of our concreting crews started work at 2.30am to complete the work ahead of sunrise.
"Also we select and use where practicable lightweight ventilated clothing and supply our staff with water coolers, water bottles and electrolytes."
Bonetti said taking regular breaks, using shade tents, tinted safety glasses, sunscreens and shade flaps to go at the back of hard hats were also being undertaken.
"We try and manage heat stress. We get ready for this weather in every summer.
"Obviously any work on the road and pavement is a lot hotter."
The SPCA is calling on people to take more care of their animals and protect them during the hotter months.
If people find an animal suffering from heat stroke, they should move it immediately into shade or an air conditioned area, and offer a small amount of lukewarm water to drink.
"Check if the ground is a safe temperature for your pet to walk on by holding the back of your hand on the pavement or sand for five seconds – if it's too hot for you, it's too hot for your pet," SPCA said.
Pet owners have been advised to ensure their animals are up-to-date with their vaccinations to ensure they are safe when out and about this summer.
Tips to keep cool
* Keep the cool air inside and sun out by closing doors, shutting windows and pulling curtains during the day.
* Open windows and doors in the evening to let the cool air in.
* Use a fan/air conditioning, even try facing a fan outside the window to blow hot air out.
* Drink plenty of water.
* Keep furniture away from external walls with at least a 10cm gap, especially if they are uninsulated.
* Keep mattresses off the floor and leave wardrobes slightly open for ventilation.