The official start of longer days and shorter nights coincides with a period of fine weather for Hawke's Bay, after a southerly flow battered the region this week.
Blustery winds of up to 100km an hour wreaked havoc on Monday, toppling trees and blocking roads throughout the region.
The polar blast was due to a southerly cold snap moving up the country, which dusted the ranges with snow.
But balmy weather is expected today, with clear skies, easing westerly winds and a daytime high of 22C.
The fine conditions will continue tomorrow, with warm northwest breezes.
Friday should be fine, with high cloud and northwesterlies which would die out on Saturday as high cloud increased.
Rain will arrive on Sunday, but temperatures should remain in the high teens.
WeatherWatch.co.nz forecaster Philip Duncan said the spring equinox had passed yesterday afternoon.
This equinox marks the official start of spring for New Zealand and also signifies the end of summer for those in the United States and Canada.
"It's the exact moment the earth starts to tilt in our favour, so we get more daylight hours and fewer hours of darkness."
It also heralded "lots of windy days," particularly warm westerly winds.
Windier weather was likely for the next four to six weeks.
"October is quite often a stormy and windy month, with conditions usually calming back down again in November as we head into the summer months."
Westerly winds were particularly warm in Hawke's Bay, Mr Duncan said, because they dried as they passed over the ranges.