"With this southerly a few temperatures down south will be a bit lower than average. There's a few fronts in this but they're pretty slow-moving and they're pretty weak.
"Places that get stuck under them, like the West Coast, will see drizzly weather on and off.
On the East Coast, a fine day is forecast for Hawke's Bay and Gisborne, Adams said.
A tongue of warm air coming in from the tropics in the west also meant some cloud on the West Coast today.
"It's like a river of warmer air coming in from the tropics."
Ashburton was slightly colder than usual for this time of year with a high of 15C, but otherwise temperatures for most of the country were as expected.
Much of the North Island was forecast to sit in the mid to low 20s today, and even Wellington was looking at a high of 20C.
Today's forecast
• Whangarei: Mostly cloudy with southwesterlies. 22C
• Auckland: A cloudy start, but fine breaks developing. Southwesterly. 22C
• Hamilton: A cloudy start, but fine breaks developing. Southwesterly. 23C
• Tauranga: Fine apart from some morning cloud. Southwest breezes. 26C
• Wellington: Fine apart from morning/evening cloud. Brief southerly. 20C
• Christchurch: Cloudy, chance light rain. Wind turns northerly. 16C
• Greymouth: Light rain. Westerlies dying out. 20C
• Queenstown: Cloudy periods, chance morning shower. Westerlies. 20C