Grab your brollies, it's going to be a wet, windy Easter

Planning a break over the Easter weekend? Put away the sunblock and dig out the umbrella, forecasters have warned.

Meteorologists say the cloudless skies and blazing sun will disappear after today, leaving a wet and windy Easter weekend.

MetService weather ambassador Bob McDavitt said the weather pattern for the past four weeks had been dominated by high-pressure systems, helping to keep the rain away from much of New Zealand.

"But today will be the last fine day and after that you will need the brolly."

The fog problems in Wellington, which had shut the airport, were a sign that the stagnant air was becoming more humid, which pointed to an imminent change in the weather.

"In the past four weeks it has been dry around the North Island, with only 7mm of rain measured in the Bay of Islands and 12mm in Paraparaumu," said Mr McDavitt.

"This is all about to change. A low-pressure system is developing in the Tasman Sea and its rain clouds are forecast to move across the North Island and the Nelson area on Thursday and Friday, accompanied by vigorous northerly winds."

As autumn begins to make its presence felt, the fading summer has been one of the most extreme. It was the coldest December since 1945 but the eighth warmest February on record.

Mr McDavitt warned that the "trough" of bad weather was likely to be followed by further periods of unsettled weather, as cooler west to southwest winds brought intense showers into many areas.

Up to 10mm of rain was expected over Easter and unfortunately the settled weather of the past few weeks "can no longer be relied upon to last", he said.

People planning to travel over the holiday weekend should get up-to-date details from the MetService website to help finalise their plans.

"We may even have to put out a heavy weather warning the way things are developing. People planning a camping holiday may want to rethink."

However, it was not all bad news.

Mr McDavitt said April was frequently a settled month and the seasonal forecast was for a dry month.

"It will be a wet start, but that doesn't mean the rain is here to stay."