The 16-year-old was last seen in the Wiluna townsite around 5pm on Tuesday afternoon, before the mercury dipped below three degrees overnight.

Sergeant Gerry Cassidy said the boy was still missing at 7pm last night and the ground and air search would continue today.

The boy was last seen wearing camouflage-printed cargo pants, a grey T-shirt, blue beanie and sneakers and is believed to be about 180 centimetres tall.

It is not known whether he is in the town or on the outskirts and police believe it is possible he has hitched a ride.

Anyone with information is asked to contact police on 131 444.