"Everything is drying up nicely."
Whanganui is expected to reach a high of 28C on Wednesday, and Metservice has issued a severe thunderstorm watch for the region from 12.30pm to 8pm.
Southeasterlies are forecast to die out by midday.
"Warm temperatures and moisture at low levels combined with cooling aloft are likely to bring unstable conditions and thunderstorms to the lower North Island.
"From Whanganui to Wellington and also Wairarapa including the Tararua District there is a risk of severe thunderstorms bringing downpours with rainfall rates of 25 to 40mm/h.
"Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips."
Horizons Regional Council media and communications manager Christine Morrison said areas were still "very soggy, obviously".
"We were potentially going to open the Moutoa floodgates at 7am, but things are going okay for now
"We are continuing to watching the MetService and doing our modelling with river levels."