Whanganui is one of the contenders for the warmest place in the country for Monday and Tuesday.
On Monday the maximum temperature will be 22C, and the same for Tuesday.
MetService meteorologist Dan Corrigan said it was a very warm forecast for the start of May, with above-average temperature highs.
"The average maximum temperature for this time of year across the records in Whanganui is 17 and a half degrees," he said.
"So it's about four and a half degrees above average."