Summer storm caused by two huge weather systems - ex tropical cyclone Fehi and southerly winds

New Zealanders hoping for a reason behind Thursday's tropical storm can look no further than two big suspects - ex-Tropical Cyclone Fehi and a system of strong southerlies.

Following the extremely hot January right across the country, the weather has made an abrupt turn for the worse, causing flooding in Dunedin, Nelson and Auckland, as well as damage in Buller and Greymouth.

The cause for this is a combination of the tropical and warm weather of Fehi headed over from Fiji, with an unfortunate addition of a system on southerly gales.

It's expected to be a rough Thursday night, before eventually calming on Friday, but this doesn't mean that summer is over.

Kiwis can't quite count on it to be sunny every day for the rest of summer, but there will still be some hot, dry days ahead, with some rainy weather mixed in as well.

Newshub.