Don't pack your brolly away – you'll need it again this summer, because the wild weather is expected to continue.
A La Nina weather pattern is still lurking in the Pacific, and the lower North Island should continue to be frequently doused in rain for the rest of summer.
"We are still looking at generally wetter weather in the north, drier in the south and a bit warmer than normal in most places through until March," Niwa principal scientist James Renwick said last night, ahead of the planned release of the agency's climate update this morning.
The West Coast had the most promising forecast for the rest of the summer.
"If you're on holiday and it's the summertime, then most places are pretty good to be in," Dr Renwick said. "But if you are looking to get in the outdoors, then this is the summer to get down to the West Coast."
Last month was one of the soggiest Decembers on record, figures released yesterday by Niwa show.
Record rainfall soaked the North Island and upper South Island, causing slips, evacuations, and ruining the holiday plans of thousands.
Wellington basked in a stunning fortnight-long stretch in the leadup to Christmas, then shuddered through atrocious gloom in a month that recorded more than twice the normal rainfall for December.
Wairarapa did not escape – Martinborough recorded 107mm of rain last month, almost twice the normal figure.
The extreme weather was the result of an increase in northeast winds, which produced cool, wet conditions in the north of New Zealand.
On December 30, a band of very heavy rain crossed most of the country, hitting the capital hard. The Moa Pt sewage treatment plant was overwhelmed by stormwater, causing overflows into Lyall Bay, which had to be temporarily closed.
The next day, heavy rain forced the cancellation of waterfront New Year's Eve celebrations.
The worst weather hit Golden Bay and Nelson in mid-December, as torrential rain caused slips, road closures and evacuations.
Nelson was soaked with six times its normal rainfall, while Takaka had eight times its usual. Both recorded their highest December totals since records began in 1941 and 1976 respectively.
And Dr Renwick was certain of one thing: "Don't stray too far from your brolly. We're in for a bit more yet."
BY THE NUMBERS
190mm – rainfall in Wellington during December, 222 per cent of normal
15.3 degrees Celsius – Wellington's average December temperature
1103mm – rainfall in Takaka over December
131mm – rainfall in Levin, compared with an average of 99mm
78mm – rainfall in Napier, compared with an average of 58mm
15.8C – nationwide average temperature in December (0.2C above the 1971-2000 December average)
31.3C – highest December temperature, observed at Alexandra on December 13
174 – sunshine hours in Wellington, 77 per cent of normal
Of the six main centres, Auckland and Tauranga were equal warmest in December, Dunedin was the sunniest and driest, and Tauranga was the wettest.