Enjoy it while it lasts - the break in the clouds will end tomorrow

Summer finally arrived in the South Island yesterday and the rain even stayed away from Auckland's major sporting events.

It should also be sunny across most of the country today - but the MetService says it won't last.

Tomorrow and Wednesday will be rainy and cold as a westerly front arrives.

Everywhere from Invercargill to Nelson experienced sunny conditions to some degree yesterday after several miserable weeks of grey skies, low temperatures and rain.

However, it did not last long in the south, with more rain and thunderstorms sending temperatures plummeting in the afternoon.

MetService forecaster Mads Naeraa said Dunedin reached 20C before rain and hail hit.

"So that's nice because it has been miserable there for a long time.

"Even Invercargill, which has certainly not been the place to be lately, got to 15 to 16C."

The sun's arrival in Timaru was enough to coax hundreds of families down to Caroline Bay, where the annual seaside summer festival was under way.

And sunscreen and hats were essential at the annual Ashburton Boxing Day races. A visible reminder that it was not the usual summer's day, however, was snow on the Southern Alps behind the course.

Christchurch also enjoyed blue skies, but a chilly easterly meant many of those brave enough to step outside remained wrapped in coats and scarves.

Further north Gisborne reached 21C and although Whakatane was pelted with 10mm of rain in two hours, the air was not cold.

Mr Naeraa said today would be fine and sunny on the east coast of both islands but cloud and some drizzle would plague the west.

He recommended holidaymakers should hold out for the first week of the new year, when a new ridge of high pressure is expected to arrive, bringing sunshine.

"But it's a long way away so don't think about it too much yet."