Metservice is warning that heavy rainfall with possible thunderstorms could be in store for Tararua and central Hawke's Bay.
Severe weather forecaster Leigh Matheson says a severe weather warning is in place tonight for the region, where ten millimetres of rain an hour has been falling for the last three hours, with some spill over into Manawatu.
Southerly gales about Wellington and coastal Wairarapa will usher through some showers overnight and there may be a smattering of snow on the Desert Road.
Meanwhile, State Highway 57 between Shannon and Levin has been closed due to flooding.
Southbound traffic was diverted through the Shannon Foxton Road onto State Highway 1 and northbound traffic is diverted at the Queen Street intersection onto State Highway 1.
Police said the rain had eased and hoped to open the road later tonight.
Council still on high alert after flooding
The Kapiti Coast District Council said the few hours without rain today had allowed rivers levels to drop, but it remained on high alert in case of further downpours overnight.
Last night,27 homes in Raumati, Otaihanga and Paraparaumu Beach had to be evacuated because of nearby streams bursting their banks.
Teams were out today cleaning up and sandbagging properties that are at risk.
Wellington Regional Emergency Management controller Scott Dray said he was keeping an eye on the sky this evening.
He said there was capacity to soak up more rain in the rivers now, but the situation would continue to be closely monitored overnight.