A large grass fire is burning on the road to Port Waikato.

Three fire crews are at the scene, with a tanker and three more crews on the way.

Two helicopters are also being sent to the scene.

Fire Service spokeswoman Dallas Ramsay said the hot weather coupled with wind isn't helping the situation.

"It certainly hasn't assisted in dampening that down, we've also got some helicopters assisting with fighting that fire."

The blaze is growing and currently covering more than two hectares.