Rain also affected the Coromandel and parts of the Eastern Bay of Plenty today and should ease through the tonight.
MetService meteorologist Ciaran Doolin said the rain was brought on by a front running along the east of the North Island.
"That has been bringing a fair bit more precipitation than we were expecting. We have been seeing that this afternoon," he said.
"It is really Northland that has accumulated the most substantial accumulations of rain."
Doolin said periods of rain were expected to stick around in parts of the South Island tomorrow.
"That is basically going to track with the motion of the cold front that is slowly making its way up the South Island tomorrow."
Main centres tomorrow
Kaitaia
Chance of heavy showers and thunder were expected today. Light winds and a high of 14C overnight.
Tomorrow: Fine spells, chance of showers and light winds are expected.
Auckland
Periods of rain and light winds hit Auckland today.
Tomorrow: Fine spells with a chance of showers are predicted. Possible light winds and a high of 23C.
Hamilton
Today Hamilton saw cloudy periods and chance showers coupled with light winds.
Tomorrow: Fine spells and light winds are expected.
Tauranga
Periods of rain and light winds hit Tauranga today.
Tomorrow: Showers could become heavy but should ease in the afternoon.
Napier
Occasional showers and easterlies tonight.
Tomorrow: The sun is out and a high of 25C is expected.
Wellington
Cloudy periods with the odd shower in the north today and light winds.
Tomorrow: Cloudy periods and odd showers stick around, coupled with a strengthening northerly.
Christchurch
The sun was out today, warming up Christchurch to a balmy 19C.
Tomorrow: Looks to be fine again but a gusty northerly.
Dunedin
Sunny with northerly winds today and a high of 20C.
Tomorrow: Cloud is expected to increase and rain could set in at night.
-Metservice