Lightning over Eastbourne
A thunder storm brewing over the Cook Strait hit Wellington about 8.15pm.
Spectacular lightning could be seen off Wellington's south coast as it approached.
About 8.30pm, hail stones the size of marbles started hammering the city.
The Metservice issued a severe weather watch for the capital, warning there may be surface flooding.
MetService forecaster Stephen Glassey said the thunder storm formed about 5pm when a southerly and northerly wind converged, creating lift.
There had already been a lot of lightning strikes reported, he said.
However, there was only a moderate risk of thunder by the time it made land later.
Wellington's eastern suburbs and Wairarapa's south coast were the most likely areas to be affected.
While the storm would come with a southerly change, the temperature was only expected to drop by about 2deg celsius, to about 10degC.
The forecast for Tuesday was for some showers and a southerly wind.