Rain and hot, muggy nights are the theme for the start of Auckland Anniversary weekend, but MetService is forecasting a return to sunny weather for the extra day off on Monday.

Clear skies are in store for the North Island today (Thursday), with temperatures forecast in the high 20s; Masterton and Taumarunui have forecast highs of 29C.

A band of rain, preceded by a southerly change, is to spread north over the South Island today as a cold front traverses the island.

A few flashes of lightning amid the rain are possible for the west coast and parts of Otago and Canterbury, with the front forecast to fizzle out by the time it reaches the top of the South Island tonight.

The southerly change brings a drop in temperatures for the South Island.

While Blenheim has a forecast high of 30C today, temperatures on Friday are forecast to only reach 20C.

Behind the front, Gore has a forecast high of 15C today, with overnight temperatures forecast to dip to 6C in the south.

MetService meteorologist Ngaire Wotherspoon comments, “The remnants of the cold front tomorrow will bring a few showers to southern North Island areas, accompanied by a slight dip in temperatures, but conditions further north remain fine and warm before deteriorating this weekend.”

As we head into Auckland Anniversary weekend, a low-pressure system approaches Aotearoa New Zealand from the northwest.

Widespread rain and strong northerly winds are to develop for central and northern parts of the country on Saturday, continuing into Sunday as the low crosses the North Island.

West Tasman is likely to experience the highest rainfall accumulations through the weekend, highlighted in the MetService Severe Weather Outlook (http://bit.ly/SWOutlook).

Further south, rain will be widespread in western regions on Saturday, before easing on Sunday as the bulk of the rain moves east.

Saturday night will be hot and muggy for the North Island.

Saturday night will be hot and muggy for the North Island, with overnight lows of 16-19C, and Sunday night isn’t looking much cooler.

“Monday is the day to be out and about for regions observing Auckland Anniversary Day, as the low moves away and skies clear.

“A strong southerly flow keeps a lid on temperatures to start, but winds weaken as the day progresses,” Wotherspoon said.