A warm air mass from the sub-tropics, and warm northwesterlies combine to create a perfect storm for sweat-inducing, sleepless nights for Hawke's Bay.
MetService meteorologist Mmathapelo Makgabutlane said Hawke's Bay was set to hit warmer than average temperatures at the weekend, and the start of the week.
On Sunday as at 11am Hastings was the warmest in the country sitting at a "very warm" 28.6 degrees Celsius with Napier not far behind at 28C.
Makgabutlane said similar conditions were expected for Monday and Tuesday.
"There's quite a warm, moist air mass from the sub-tropics hitting New Zealand and for the East Coast, particularly for Hawke's Bay the wind direction, a northwesterly.