The Southerly sweeping the country is knocking temperatures down from the high twenties on Thursday, to the low teens.
Ashburton went from 27C at 3pm on Thursday, to 13C around 5pm.
Blenheim reached a summery 29.5C on Thursday, the warmest since March, but Friday's high is expected to be just 18C.
So, it'll be a wet and blustery day for many, and the heavy rain watch for Hawke's Bay and Te Tairāwhiti is expected to become an orange heavy rain warning on Saturday.
MetService meteorologist John Law spoke to Corin Dann.