KEY POINTS:
Swimwear stores are racking up record sales as the summer heatwave shows no sign of stopping.
Tony Cederwall of the Beach Hut/Jennifer Dean Factory Shop in Mt Eden said he was enjoying the best December and January since buying the business in 1990.
"We have 10 stores in the North Island. It's been going crazy. It's broken all records. We are up between 30 and 40 per cent."
Cederwall said he was restocking all the time. "The last two seasons have been a bit patchy, but this year it's been a long, hot summer, and it doesn't look like it's going to stop."
The situation was the same in the capital, according to Splash swimwear manager Jhana Millers.
"It's been really busy compared to last January and it's definitely because of the weather.
"We have been cleared out of swimwear and have had to restock far more than we usually do."
Buyers fuelling the swimwear boom have made the most of above-average sunshine hours for most of New Zealand, according to figures released by NIWA this week.
Sunshine hours were more than 50 per cent higher than normal in Southland and Otago and at least 30 per cent higher than normal in inland parts of the South Island.
The rest of New Zealand experienced average sunshine hours, except Northland where cloudy skies prevailed.
Air temperatures were near or above record levels for much of the country, especially Waikato, King Country, Nelson and inland South Island.
Mean temperatures were at least half a degree above average in the east of the North Island, and between one and two degrees above average in the rest of New Zealand.
Average maximum temperatures were more than two degrees above average from Waikato to the central Plateau. The national average temperature of 18.3C was 1.3 degrees above average.
The month's hottest temperature was a blistering 34.8C, recorded on different days at Timaru Airport and Waione, near Martinborough.
But the soaring temperatures have meant extremely low rainfall in northern areas from Auckland south and the coastal northeast of the South Island.
Water restrictions have been reported in Hamilton, Thames, parts of the Coromandel and south Taranaki.
The Government has called a meeting on February 12 to discuss the impact of the drought.
There are no plans to limit water use in Auckland, where Watercare supplies more than 370,000cu m (cubic metres) of water daily from 10 dams, one river and one underground source.
But Jenny Prattley of Reds Water in Whangaparaoa expected this month to be busy for her tank water supply business.
"It's been a quieter Christmas and New Year because people are away. We really notice when people come home from holiday because it's getting really busy."
Swimwear and water outlets weren't the only businesses with tills ringing hot.
Andy Goodall of Comfort Air Conditioning in Tauranga said his firm had enjoyed a 20 per cent rise in business. It was shaping up to be the best summer for sales in 25 years.
"I've had people screaming that the temperature is 38C in the office. Workmen have walked off sites because the ceilings are too hot. Ceilings are 15 to 20 degrees warmer than outside."
The summer is set to sizzle on into March, according to MetService weather ambassador Bob McDavitt.
He said air and sea temperatures were likely to stay well above normal as a La Nina weather pattern brought larger highs later into summer.
This month would bring similar humidity levels to last month plus periods of high rainfall, which could cause flooding in parts of Northland.
"But the places that need water and are experiencing a drought, like central South Island, don't look to be getting much rain apart from the odd shower. It won't bring much relief."
