Northland had a very interesting weather pattern last year, according to Northland Regional Council hydrologist Jason Donaghy.
"We had a dry start and finish to the calendar year with a drought at the beginning of 2017, which was balanced out by a stormy autumn and consistent winter rains," he said.
Winter was perceived as wet but rainfall totals were not significantly high.
"What was different was the amount of rain days — essentially it rained for more days than normal," Mr Donaghy said.
"This was reflected in the groundwater systems that were above normal levels after the winter season. The two previous years, groundwater levels were below normal levels due to the dry winters.
"Moving on to spring the rain stopped and the Dargaville/ Pouto/ Ruawai area started to dry out. This was exacerbated by the hot air and soil temperatures in December with soil moisture deficits dropping to levels normally seen in late summer."
Early in January this year the pattern of blocking highs was broken by the first deep low drifting down from the north Tasman.
"We now have had multiple systems that have bumped the January rainfall to well above normal," Mr Donaghy said.
"It was the second wettest January with 280.5mm of rain recorded at the Managkawakawa gauge north of the Mangamukas. The maximum was 293mm recorded during Cyclone Wilma in 2011."