This would be moving across the country, hitting Hawke's Bay overnight with spots of showers, before the weather cleared up for several days.
"That pattern is going to repeat itself," Mr Hines said. "It will be nice on Monday and Tuesday, but when the next weather system comes in there'll be some more [scattered rain]".
Rain overnight was expected to clear this morning for the urban areas of Hastings and Napier, with winds turning northwest and the day becoming fine, with a high of 20C.
Similar weather was expected tomorrow, with another high in the 20C's, as well as high cloud increasing and northerlies picking up. An overnight low of 12C was expected.
Although the weather in Central Hawke's Bay was expected to be similar, temperatures would be lower, with highs of 18C. The high in Wairoa was forecast to be about 15C.
The weather pattern would begin again on Wednesday, when some scattered rain would develop with northerlies becoming strong and turning into a lighter westerly overnight. The high for Hastings would drop, at an expected 18C.
By Thursday morning the rain would clear, with fine breaks developing and westerlies.
Friday was expected to be mainly fine with a few coastal showers, and winds turning southwesterly.
As the warm spell eased off temperatures would fall in line more across the region - with expected highs of 16C in Hastings, 14C in Waipukurau, and 13C in Wairoa.
Although this week's weather would be "a bit toasty for August", Mr Hines said this was not a sign winter was coming to an end.
"There's plenty more chilly weather on the horizon."