Yesterday was the hottest so far this summer, with Gisborne experiencing the highest temperature in New Zealand at 37 degrees Celsius.
MetService recorded temperatures of 35C in Napier, 34C in Hastings and Blenheim, 33C in Whakatāne, 32C in Tauranga, 31C in the Bay of Islands and 30C in Whitianga, Nelson and Hanmer Springs.
Auckland was sultry on 27C, while Wellington reached 24C and Christchurch peaked at 25C.
The National Institute of Water and Atmospheric Research (NIWA) said 31 January was also the warmest day in 2019 and 2018.
MetService said rainfall was at record low levels in many regions in January.
Parts of Northland, Auckland, Waikato, Coromandel, Bay of Plenty, Nelson and Canterbury received less than 10 percent of normal rainfall for January.
Most of the North Island, and northern and eastern regions of the South Island, recorded less than 35 percent of typical January rainfall. Gisborne and Hawke's Bay had only about half the usual rainfall.
Here's the maximum temperatures across Aotearoa New Zealand for Friday 31st January. Gisborne was the hottest spot with 37C. ^GB pic.twitter.com/BcoH0pgOHy— MetService (@MetService) January 31, 2020
NIWA said drought conditions are being experienced in the upper North Island and severe drought had hit Aupouri peninsula and parts of Great Barrier Island.
"There are currently no areas in the North Island where near normal or above normal soil moisture levels are found," NIWA said.
The MetService prediction for February is well above average temperatures in the North Island, except for Wellington, which is expected to get temperatures around average.
In the South Island, heat wave conditions are predicted this weekend and early next week, with a colder spell expected from Tuesday.
Will the extremely dry areas of New Zealand receive much-needed rainfall anytime soon?— NIWA Weather (@NiwaWeather) January 31, 2020
There is an opportunity during the second half of February.
Insights from Chris & Ben pic.twitter.com/xM0EPDXlOG
The first half of February is expected to continue being drier than usual in all North Island regions, Nelson, Marlborough and Canterbury.
"The odds of getting some useful rain in the gauge increase in the second half of the month, but we expect rainfall to be rather unreliable," MetService said.
The West Coast of the South Island, Southland and Otago, can expect rainfall to be close to normal in February, with next week delivering more rain than usual.
At the beginning of January, the ocean was "markedly cooler" than usual due to strong winds. High temperatures and a lack of wind lifted sea temperatures to 1 to 2 degrees above normal in the Tasman Sea and around New Zealand by the end of last month.