The spring-like warm spell which has seen temperatures across parts of Hawke's Bay hit 21C is set to dissolve back to more wintry conditions on Monday - although by mid-week the unseasonable warmth is forecast to return.

And the pattern of sunshine and northwesterly wind fronts is showing signs of sticking around for the rest of the month.

August in the Bay is set to deliver "above average" temperatures, WeatherWatch analyst Philip Duncan said.

"We seem to be seeing an early spring pattern defined by windy westerlies," Mr Duncan said.


"The signs were all there August would continue the pattern of the past winter months warmer and windier."

While it was looking to be warmer there would still be short wintry bursts as well as more winds, he said. Today those winds were forecast to emerge in a big way across the Bay with strong northwesterlies, possibly reaching gale force in some places.

Temperatures were again likely to nudge 21C as they did yesterday, and while the winds would linger tomorrow as well as bringing some brief rain, temperatures across the twin cities were likely to reach 19C.

But on Monday a showery visitor from the south is forecast to spoil the spring party dropping temperatures to 12C.

It would however echo what Mr Duncan described as "short wintry bursts" and by Wednesday the northwesterlies bringing sunshine and temperatures of 16C and 17C would return and remain into the weekend.

While the long-term pattern will still see southerly changes strike through August the month would see more westerlies.

"The first half of August sees a lot of windy weather, especially for central, eastern and southern parts of New Zealand," Mr Duncan said.

In global terms, the forecast temperature of 21C in Napier and Hastings today was the same as for Buenos Aires, 2C higher than Perth in Western Australia and 4C higher than Edinburgh which is "enjoying" a Scottish mid-summer.