"Hotober" has made way for the cooler temperatures we usually feel at this time of year in a dramatic reversal which saw the mercury plunge by 20C in some places today.
Strong north westerlies yesterday brought summer-time temperatures unusually early, smashing records for this time of year.
Kaikoura reached 32.2C, Wairoa 31.3C and Timaru 29C.
The seaside town of Kaikoura smashed the previous October records of 27.8C.
"Usually it's broken by 0.1C or 0.2C. This was particularly significant," said MetService meteorologist Lisa Murray.