Heavy rain has caused a landslide that is blocking the road between Titirangi and Waiatarua, west of Auckland.

The Fire Service said about three tonnes of dirt, rock and trees blocked Scenic Drive this evening, and emergency services were working to clear it.

Police said the road would remain closed overnight and diversions were in place at Shaw Road and West Coast Road.

Fire Service shift manager Jaron Phillips said it had also been called out to eight homes that had been flooded.

He said the flooding was mainly in west Auckland but other areas of the city had also been affected.

Crews were also dealing with a slip on State Highway 25 in the Coromandel, between Waihi and Whiritoa, he said.

He said one-and-a-half lanes of the road were currently blocked.

MetService said northwest gales were expected in Northland, Auckland and Coromandel overnight, with a possibility they could reach severe gale force, before turning into westerly gales on Friday evening.

Eastern Bay of Plenty could also get heavy rains overnight.

WeatherWatch.co.nz said the number of hours of rain in Auckland over the last two days made it "one of the wettest 48-hour periods the city has had this year so far".