This dipped to an overnight low of 3C, resulting in frosts across the region. Mr Adams said frosts were more likely when temperatures fell below 4C.
While frosts are dreaded in growing season, Hawke's Bay Fruitgrowers Association chairwoman Lesley Wilson said at this time of year, frosts were welcome.
Except for some kiwifruit, most crops had been picked already, she said.
"The frosts have arrived a bit earlier, but it just means it's an early start to winter chilling," she said. "If we don't have winter chilling it can mean lower numbers the next year, and its good for picking at the other end".
"Its actually good news."
More frosts were expected this morning, with yesterday's high of 12C sinking to 3C overnight.
A severe weather watch was in place for most of the region yesterday, with gales reaching 100km/h about the coast forecast, but that was lifted in the afternoon.
With cloud clearing last night Mr Adams said there would be a "real risk" of more frosts in the first part of this week.
The weekend's cold snap was also reflected in dustings of snow on the Kaweka and Ruahine Ranges.
With snow settling on the Desert Rd - so much that it was closed on Saturday - Mr Adams said places above 800m in Hawke's Bay could have also experienced a flurry.
The rest of the week is expected to be warmer.
Today was forecast to be mainly fine with isolated coastal showers clearing, and light winds. Temperatures could reach a high of 14C during the day, but plunge to 0C overnight.
Tomorrow and Wednesday are forecast to be mainly fine with a few northerlies and temperatures reaching a high of 18C.
No change in the weather is expected towards the end of the week, although temperatures will rise to a high of 19C, dropping to 7C overnight.
