Hastings will also be hit with a frosty morning, plummeting to 2C in the early hours.
Similar conditions are expected heading into Tuesday, with a high of 13C for both Napier and Hastings and 3C expected overnight.
Wednesday will be "mostly cloudy" with a few isolated showers in Hastings, and a winter freeze will be felt with an overall low of 0C predicted for Napier and Hastings overnight.
Murray advised residents to "wrap up and keep the firewood stocked" as the region prepared for an increasingly chilly week.
The cold snap came off the back of a wet spell last week, with 304mm of rain recorded accumulatively across the region from Mahia, Napier, Hastings, Takapau Plains though to Cape Turnagain.
Hawke's Bay Regional Council Principal Climate and Air Scientist Dr Kathleen Kozyniak said the heavy downpours on the "Heretaunga Plains gave us our average June rainfall".
"Storm water levels were pretty low for that time before the rain so it was pretty needed" she said.
"It was a good bump up".
Vice president and dairy chair of Hawke's Bay Federated Farmers, Matt Wade, said the rain was "most welcome" after the unusually dry months leading into winter that meant stock-feed was having to be used earlier than normal.
"We had reports of between 70-100mm of rainfall around Mahia, and 85mm near the Takapau Plains," he said.
"It was pretty slow and steady and there was no reported damage".
He said the heavy rain had helped "kicked things along".
