"Whanganui will stay in double figures all weekend and there will be light breezes," Fernandes said.
"There will be more low cloud on Sunday and the showers are likely in the afternoon although they are expected to be light."
The predicted high for tomorrow is 20C with an overnight low of 12C.
There will be more of the same for the public holiday on Monday when it is likely to be mostly cloudy, with a shower or two and light winds.
A maximum temperature of 22C is forecast followed by an overnight low of 13C.
For those planning to head to Ruapehu over the weekend, Turoa and Whakapapa will be open although some facilities are closed.
Conditions for visiting Tongariro National Park are also good with light winds and no hazards predicted for the weekend.