The forecaster says while most of the country will be warm, Central Otago and inland Canterbury are in line for temperatures heading north of 30C.
"As a result, MetService Heat Alerts have been triggered for Wānaka and Alexandra."
The heat alert system is designed to focus on "top end" heat, MetService says, and it's aimed at warning people of possible impacts to health when the temperatures rise.
"Extreme heat during summer can be draining and have an impact on people’s daily lives – especially their health and wellbeing."
The forecaster's website shows predicted highs of 32C for Alexandra and 31C for Wānaka. That's as much as 10 degrees higher than coastal areas - Dunedin is in line for 22C and Oamaru 21C.
The scorching heat will be short-lived, however, as a weather system approaches from the west on Wednesday, bringing rain at night.
MetService meteorologist Mmathapelo Makgabutlane said: “Brief rain spreads up the South Island on Thursday, bringing a cooler day for many."
The good news for sun-lovers is that temperatures look set to climb again going into the weekend.
- APL
