MetService meteorologist Rob Kerr said a few showers were expected along Northland's west coast, particularly in Dargaville and Kaitaia, over the weekend.
Today should see light southerly winds and clear skies while light easterlies are predicted for tomorrow.
"Northland will still be one of the warmest places in the country despite daytime temperatures of around 13C this weekend and around 3C to 4C overnight," Mr Kerr said.
"Areas south of Hamilton will really struggle with the cold weather, while the east coast in Northland like Whangarei and Paihia will tend to be colder than other areas [in Northland]."
MetService records showed Kaitaia Hospital had the lowest temperature in Northland yesterday morning at 2.5C, but the temperature was likely to be lower inland and in high spots.
Mr Kerr said overnight temperatures of 2C to 3C in Northland at this time of the year seemed reasonable.
"Clear skies will likely bring frosts on the ground because the slow air allows cold air to sink in the ground.
"Also, short days don't give the sun enough time to warm the ground."
Rain is expected to fall throughout Northland in the middle of next week before turning into showers heading into the weekend.