UPDATED 11.37am: A battle is on to save houses in the path of a large fire in Northland, which has been burning out of control for a week.

The blaze at Kelly's Bay on Pouto Peninsula covers around 205 hectares.

Incident controller John Sutton expects the wind will pick up today.

"There's a cluster of houses actually at the beach but probably of more concern is there are isolated houses closer to the edge of the fire on the other side of the road, which would be our first priority in terms of threat."

Sue Reed-Thomas at the Department of Conservation is concerned the wind could get stronger today.

"That could put some of those residents at risk. We're staying on our toes."

Reed-Thomas says by last night, crews were becoming exhausted.

"The guys that have been out on the fire ground all day tucking into their dinner, ash-covered faces."

However, the rugged terrain has broken the wind somewhat, slowing the fire's spread in parts.