Clear skies and light winds the past few nights had provided "good conditions" for fog.
But a front moving up the country today would bump the fog along, although it could hang around in places until mid-morning.
The front was already bringing heavy rain to the South Island's West Coast and would move quickly up the North Island today, spreading rain to many areas with the heaviest falls in the west.
Rain would develop in Auckland from morning, possibly becoming heavy and thundery from the afternoon before easing to a chance shower towards the evening as northerlies changed to westerly. A high of 16C was forecast.
The strong winds coming with the front reduced the chance of fog forming over the next few days, Lee said.
The front would move off the country by tonight, before another more significant front arrived in the South Island early Saturday.
Heavy rain was forecast for Westland and Fiordland, before moving north through Buller and Nelson, and on to the North Island by Sunday.
Gale westerlies would accompany the front, also raising temperatures a notch above average.
As the front moved on the North Island it would still be "packing a punch", Lee said.
"Most parts of the country will see some rain this weekend, with plenty of wind and rain forecast in the North Island over the second half of Sunday."
Today's weather
Whangārei
Rain developing morning, possibly heavy and thundery from afternoon, easing to a chance shower by evening. Northerlies dying out evening. 18C high, 8C overnight.
Auckland
Rain developing morning, possibly heavy and thundery from afternoon, easing to a chance shower towards evening as northerlies change westerly. 16C high, 10C overnight.
Hamilton
Early fog. Rain from late morning, easing in the evening as northerlies die out. 15C high, 9C overnight.
Tauranga
Cloudy. Rain developing afternoon, easing evening then clearing. Northwest breezes. 16C high, 9C overnight.
New Plymouth Rain from about midday, possibly thundery and squally, clearing evening as strong northerlies change westerly. 15C high, 11C overnight.
Napier Cloud increasing, then some rain in the afternoon or evening. Northwest breezes. 17C high, 8C overnight.
Whanganui Becoming cloudy. Periods of rain from afternoon, easing evening as northerlies change westerly. 17C high, 11C overnight.
Wellington A morning shower or two, then rain from late afternoon to early evening. Northerlies. 13C high, 11C overnight.
Nelson Occasional rain developing late morning, chance heavy afternoon, clearing evening as northerlies tend westerly. 13C high, 4C overnight.
Christchurch Cloudy at times. Northeasterlies, strengthening for a time afternoon. 13C high, 3C overnight.
Dunedin Cloudy, with early inland frosts. A few spots of afternoon rain. Becoming fine this evening. Northeasterlies dying away. 11C high, 7C overnight.
