Residents in New Zealand South Island's Canterbury region struggling to cope with Saturday morning's devastating earthquake will also have to cope with a storm, forecasters said.

The 7.1 magnitude quake has left many homes exposed to the elements, which are expected to take a turn for the worse with gales forecast for Sunday afternoon.

WeatherWatch.co.nz said strong winds would increase during the day, with severe gales gusting to 130 kmh possible later in the day.

MetService was also watching the storm, issuing a severe gale warning for Christchurch, predicting winds averaging 65 kmh (gale force) with gusts to 130 kmh.

A spokesman said the winds of that speed can be damaging and with many buildings extensively damaged, it could cause a major headache for emergency services, the NZPA reported.