The cordon keeping hundreds from their Port Hills homes may soon be reduced despite authorities holding fresh fears gusty winds may still pose a threat.

Christchurch Civil Defence said a priority was to plan a way to allow evacuated residents back into their homes where it was safe do so.

Work was being done to shrink the cordoned area around the fire, and a decision on which cordons would be lifted was expected this afternoon.

Some were starting to be relaxed just before midday.


However, the council said extreme heat in the ground and in vegetation still posed a risk of flare-ups.

Despite the morning drizzle, the wind was expected to increase this afternoon and any dampness would be dried out. Forecast north-easterly winds with gusts of up to 50 km/h are expected across the city this afternoon.

Firefighters breathed a sigh of relief as they woke to slightly cooler weather and higher humidity today, but the fire was still being described as largely contained but not yet controlled.

Today diggers were creating firebreaks in several areas. Fire retardant would be dropped in areas the diggers could not access.

Meanwhile tonnes of fire-stopping foam to help put out the Port Hills wildfire is due to arrive in Christchurch late this afternoon.

The New Zealand Defence Force said the 15 tonnes of fire retardant material was scheduled to arrive at 5.20pm from Melbourne and should make a significant dent in helping extinguish the blaze that has now claimed 2075ha.