MetService is warning people to rug up this month as June shapes up to be cooler than usual.
Meteorologist Georgina Griffiths said temperatures would swing between average and below average, and the first and last weeks of June looked particularly cold across much of the country.
She said it would be colder than the national June average of 8.4 °C and that temperatures this month would be in sharp contrast to last June, which was the warmest on record for New Zealand.
"We're seeing a big change around the seasons at the moment cooling off rather rapidly faster than is typical for this time of the year," she said.
"And we've got an El Nino in the tropics, which is basically trucking along going gangbusters strong."
She said June showed potential for a good ski season.
Over the last month, El Nino has strengthened in the tropics, reaching levels not seen since 1997/98.