The North Island was peppered with almost 12,000 lightning strikes last night as thunderstorms and torrential rain brought floods and caused homes to be evacuated.
Thunderstorms were tracked mostly around northern parts of Auckland and central eastern parts of the North Island, WeatherWatch head weather analyst Philip Duncan said.
At the peak of the storms a few thousand lightning strikes were detected in an hour.
Downpours led to the Fire Service being called to more than 40 incidents, mostly flooded homes, between 6.30 and 7.30 last night in Glen Eden and Titirangi.
Fire Service spokesman Paul Radden said extra appliances were sent to the suburbs, including those equipped with machinery to pump floodwaters.