From rainbows and lightning to hail and flooding, residents in the central North Island have been dealt a mixed bag of wild weather this afternoon.

Metservice issued a thunderstorm warning at 1pm for Waitomo and Waikato and across to Taupō and the Bay of Plenty.

It's due to expire at 9pm tonight, meaning the heavy weather that triggers Metservice to issue such a warning would have passed.

MetService meteorologist Aidan Pyselman said the wild weather started to fire up around 2pm but is now on an improving trend, with the thunderstorms tracking northeastwards across the Bay of Plenty and then offshore.

"Moving into tomorrow, it's looking pretty good. All the action has been this afternoon and evening," he said.

"Inland places like Otorohanga and Putāruru ... they were the ones that saw a lot of thunderstorm activity, localised downpours, quite large hail and thunder and lightning."

Waitomo Caves resident Kit Blackwood said his home was battered with hail for several hours this afternoon.

"Just the ridiculous sound [of the hail hitting the roof], it was so loud," he said.

"The hail was bigger than your average marble. It was real crazy," he said.

"It went over a couple of waves and faded away," he said.

"After it disappeared there were clouds above us that were twirling in on themselves. They came in from the east and hit an invisible wall and twisted back on itself if that makes sense."

Further south a Metservice heavy rain warning is in force for the Hawke's Bay area, north of Napier.

Residents have been told to expect a further 40 to 60mm of rain on top of what has already fallen today.