With Spring looming, pollen season has arrived for much of the country.
Metservice meteorologist Lisa Murray said while there was another week of winter left, some parts of the North Island had relatively warm weather.
Auckland's maximum temperature on Thursday would be 17C and Kaitaia would be 18C.
With these warmer temperatures, pollen season has arrived.
Pollen expert Dr David Fountain told Metservice it was mostly from pine and some hazelnut trees.
He expected it to spread across the country over the next few weeks.
Murray said while there were warm temperatures, some areas of the North Island would get "decent rain" this week.
"With a low, strong winds and decent rain, it's bringing in warmer air which holds more moisture.
"It looks like we could get heavy rain in the western area of the North Island," she said.
There would also be strong north-westerlies in the western areas of the North Island, moving to the eastern areas by the end of the week.
The Canterbury high country, Southern lakes and Central Otago may get a dusting of snow but it was "nothing extreme", Murray said.
• Today: Fine. Southwest breezes. 16C.
• Tomorrow: Occasional rain from afternoon. Westerly change. 15C.
• Today: Fine. Light winds. 17C.
• Tomorrow: Rain at times. Northerlies changing westerly. 16C.
• Today: Patchy fog clearing to a sunny day with light winds. 14C.
• Tomorrow: A few showers develop afternoon. Southeasterlies. 12C.
• Today: Mainly fine, but drizzle in the evening. Light winds. 14C.
• Tomorrow: Occasional rain or drizzle. Northeasterlies. 10C.