Fire crews are working against time to control a major fire in Canterbury foot-hill

At least seven crews have monitored a 980 hectare fire at Castle Hill that's been burning since Thursday - destroying a wilderness hut in its path.

Fire and Emergency Incident Commander Brian Keown says they want to contain it before the extreme fire danger day tomorrow.

MetService has issued an Orange Wind Warning from early tomorrow morning.

Ground crews will be increased today - there will be five helicopters and no fixed-wing aircraft.