Key Points:

While the heatwave in most parts of the country has put firefighters on alert, Southlanders were experiencing a phenomenon of a different kind.

Queenstown residents reported a "strange orange glow" in their region, caused by smoke from the Australian bushfires.

"At present the air is blowing directly from South Australia to south New Zealand, and it is taking all that smoke with it in the cloud," MetService weather ambassador Bob McDavitt said.

Temperatures have been well into the 30s in Canterbury, Wairarapa and other parts of the country, but cooler temperatures are on the way in the next few days, Mr McDavitt said.

"Sunday [yesterday] will be the warmest day and from then on it will be downhill with lower temperatures.

"We haven't exceeded the temperatures we got last week, as last Sunday was warmer than this Sunday."

High temperatures, strong winds and low humidity were a perfect recipe for fires, he said.

The MetService was advising people to check fire and water restrictions in their areas.