There was the possibility of frosts overnight tomorrow and on Thursday, he said.
"It's not going to drop down a huge amount but it is going to be chillier than it has been over the last couple of days," the meteorologist said.
"Going into Wednesday it's probably looking like the better day of the week, there'll probably be bits of blue sky across most of the country, however there is going to still be a few showers around."
A series of fronts moving on to the country on Thursday would make the weather deteriorate for most areas going into the weekend, Mr Doolin said. There was also a chance of severe gales in Wellington, Marlborough Sounds and Wairarapa on Friday.
WeatherWatch head analyst Philip Duncan said southwest winds blowing in would bring cooler temperatures today.
He said tomorrow would see relatively clear weather for most of the country.
"It's not cold ... but it is back to about average for this time of week. And as a result we've got average conditions," he said.
A severe weather watch was issued by MetService for heavy rain in Northland, Bay of Plenty, Waikato down to Taranaki and across to Tongariro National Park yesterday afternoon.
Northland police urged motorists to take care on the roads, with rain making driving "treacherous".
There were three crashes in Northland yesterday morning - the first on State Highway 14 near Dargaville, followed by one on the Brynderwyn Hills and one at Bulls Gorge near Kerikeri.
Northland road policing manager Inspector Wayne Ewers said motorists needed to slow down and leave an appropriate following distance.
The area had experienced several fine days in the past few weeks so yesterday's rain had made the roads more slippery, Mr Ewers said.
"The posted speed limit is not a target and it takes a lot longer to stop if you have to put the brakes on when driving on a wet road."
Today's forecast
Whangarei: Cloudy periods with chance of rain. High 20C, low 13C.
Auckland: Cloudy periods with the chance of showers. High 18C, low 13C.
Hamilton: Cloudy periods with the chance of showers. High 19C, low 9C.
Tauranga: Morning cloud then fine with breezes. High 20C, low 10C.
Wellington: Fine with evening showers. High 18C, low 9C.
- Source: MetService