Storms that passed through the province Monday night caused severe damage to SaskPower's transmission and distribution systems in the Prince Albert, Meadow Lake and North Battleford areas.
It's estimated Meadow Lake and North Battleford will have power restored in 18 to 24 hours, SaskPower said over the noon hour.
However, Prince Albert residents won't get their power back for 24 to 48 hours, with rotating outages.
The utility asked customers to be patient, saying it has called in contractors to help get the work done as soon as possible.
Earlier in the day, Prince Albert's Victoria hospital was on emergency backup generators.
The hospital can still perform emergency procedures, but all elective surgeries have been cancelled.
Other hospitals and long term care homes in the health region are also on backup generators as they cope with the power outage.
The region is asking people avoid the emergency ward in Prince Albert if at all possible.