Kiwis should keep their sunglasses and sunblock handy, with MetService saying beach weather is on the way for New Zealanders along with scorching temperatures.
It comes as high pressure is centred over New Zealand meaning Kiwis can expect a period of fine weather.
MetService said the North Island should have the pick of the weather on Monday, with warm temperatures on the way.
Gisborne is expected to be the hottest place in the country on Monday reaching 27 degrees, while Whitianga isn't far behind on 26C.
Large parts of the North Island are scheduled to reach 24 degrees and should see a fine and sunny day.
But for the South Island, temperatures are expected to be cooler for most of the island, with many places forecast to reach the high teens.
But at the bottom of the South Island, Alexandra and Wanaka are both expected to have a cracking day, reaching 26C.
But the temperatures are really set to crank up as the week goes on, with MetService meteorologist John Law telling Newshub he wouldn't be surprised to see a few places reach 30 degrees on Tuesday.
He said there is warm air over the country, which will continue to drive the temperatures up with Wednesday and Thursday shaping as being the hottest days of the week.
"We've got warm air feeding in from the north and the west, so it's that warm air, which is our good base layer, particular for those areas in the east, those north-westerly winds helping to just push those temperatures higher up as well," he said.
"I think particularly for Wednesday in the South Island, it's going to be a pretty hot day with some spots, places like Alexandra, forecast to reach highs of 32 degrees."
Law said it would be a safe bet for Kiwis to make beach plans for most of this week with a period of settled weather on the way.
But he did warn, the high pressure will start to "push away" when the weekend rolls around meaning some bad weather could be on the way.
"I think this week particularly across the North Island the high pressure is firmly in place," he said.
"For the South Island, Friday is looking like a cooler day again. So I think the hottest days will be Wednesday and Thursday and then it's a case of watching another system moving in from the northwest as we head towards the weekend. So that's all going to be all to play for, for Christmas Day itself."
