Police are warning people to remain vigilant when opening windows overnight in an attempt to gain respite from the high temperatures.
MetService meteorologist Rob Kerr said temperatures were likely to reach 22 degrees Celsius throughout the night, rising to around 29 degrees Tuesday day-time and 30 degrees on Wednesday.
"It'll be a warm night tonight, with temperatures sitting around 22 degrees throughout," he said. "Looking into tomorrow, you may see a period of rain in the late afternoon and into the evening affecting the Hawke's Bay region, but the showers should largely hold off later in the week."
District Prevention Manager Inspector Dean Clifford said people should be cautious when attempting to cool their properties and cars, with burglars and thieves active.
"While keeping doors and windows open is great for staying cool, it can be of interest to those looking for easy and unwelcome access," he said.
"It is important to close and lock windows and doors as a deterrent and to be mindful of money and other valuables being left in open view within your home or vehicles.
"People may also relax their approach to vehicle security due to the long evenings. Keeping your vehicle secured can help to prevent opportunistic crime."
Clifford also suggests keeping in contact with your neighbours and letting each other know if you notice anything unusual, stating "Neighbourhood Support groups can be particularly useful for this purpose."
If you see any suspicious behaviour, safely record details like car registrations and contact Police immediately by calling 111. Information can also be provided anonymously through Crimestoppers on 0800 555 111.