, icecream sellers reported queues, while beaches and pools around Hawke's Bay became the spot of choice for school holidaymakers.
Napier peaked at 23.6C, down from Sunday's soaring top temperature of 27C.
With high temperatures comes high foot traffic according to Danish Delight Napier Ice Cream, which welcomed three times its usual customer haul on its first ever day of school holiday trading.
Danish Delight owner Rebecca Tostevin said she spent the day away from the Marine Pde shop, however, after running out of stock earlier than anticipated.
"We expected more people around, but today is a whole new level," she said this
afternoon.
"We make our own waffle cones and I've been frantically making up mixture after running out. I have never had to make more mixture up during the day since I opened the business six months ago."
MetService meteorologist Andrew James said both Napier (18.3C) and Hastings (18.8C) had exceeded their average October temperature across the last seven days.
However, James said this is not uncommon for this time of year.
"While temperatures are above average, it's not particularly unusual at this time of year as spring is very changeable," he said. "You get days above and below average."
Both Hastings and Napier featured in Sunday's top three highest temperatures nationwide, with both districts reaching highs of 27C.
Kaikōura Airport was the only place to record a higher temperature (28.5C) than the Hawke's Bay hotspots.
James said the average daytime high in Hawke's Bay in October is 19C.
Danish Delight Napier Ice Cream welcomed three times its usual customer haul on Sunday. Photo / Warren Buckland
Tostevin said Mondays are usually spent cleaning up after a busy weekend, no matter the time of year.
"Monday's are dead as anything," she said. "We've got two kids working, when we'd usually only have one - both have been flat-out serving customers all day."
The icecream shop owner said chocolate icecream had sold at twice the rate of its nearest competitor.
Spokeswomen from Hastings District Council and Napier City Council said there were visitors aplenty at swimming pools across the region.
"Both the Clive War Memorial Pool and Flaxmere Pool have been busier than usual today with the hot weather," the HDC spokeswoman said.
The NCC spokeswoman said an already busy Napier Aquatic Centre had seen another surge today
, the facility reaching its limited capacity early on.
Napier's Bay Skate also said their day had been "crazy", with an in-house survey suggesting the majority of visitors had come from out of town.
"The Rail Jam competition on Saturday saw one of our busiest days ever," a spokesman said.
The HDC spokeswoman also recommended locals visit Frimley Park for its shaded areas or even their local library to stay cool.
Napier locals enjoying a spot of early morning fishing in Westshore before temperatures began to climb across Hawke's Bay. Photo / Paul Taylor
While temperatures will remain high on Tuesday, James warned the Hawke's Bay public rain and a drop in temperatures will dampen the moods by midweek in a "shock to the system".
Hastings and Napier will retain their high temperatures on Tuesday, with expected peaks of 26C and 25C respectively, before a drop to highs of 20C on Wednesday and 14C on Thursday in both cities.
Rain will begin to develop in both districts on Wednesday morning, with fine spells expected in the afternoon.
Occasional rain will continue into Thursday with southerlies and overnight lows of 6C also expected, and there is potential for morning frost on Friday and Saturday.
