The massive Canadian wildfire that displaced thousands of people in Alberta has officially spread to neighbouring Saskatchewan.

The fire is now 4,830 sq km (1865 sq miles) and has expanded east.

It has burned about 7.8 sq km (3 sq miles) in the province so far, the CBC reports.

The nearest village is more than 30 km from the border, but smoke and ash could be a concern for the town of La Loche, Saskatchewan.

There are currently nine fires in Saskatchewan.
If the fire or air quality does not worsen, evacuees from fire-ravaged Fort McMurray may start to return home as soon as 1 June, Alberta premier Rachel Notley has said.

The timeline for more than 80,000 people returning to their homes is "conditional", she said on Wednesday.

The re-entry plan will allow for some residents to come back 1 June and all residents to return by 15 June.

In order for the timeline to be followed, five conditions must be met,  Notley said.

--The fire can no longer be an "imminent threat" and air quality must be safe
--The hospital must be open and able to provide basic services
--Fire, police and ambulance services must be restored
--Roads must be open to traffic and natural gas and electricity must be restored
--There must be access to food, potable water, banks and pharmacies

 Notley suggested residents bring food and drinking water, portable coolers, boots, flashlights, batteries and cameras back with them.
Schools are not expected to reopen until September.

"Let me be clear that this re-entry plan is voluntary. It's a matter of allowing those people who wish to return on a voluntary basis to do so in a phased and cautious way. We anticipate that many people will not return as early as June 1, and we will support them in that decision," said  Notley.

She warned that the date would be pushed back if conditions change.

The fire began on 3 May and destroyed more than 2,400 homes and buildings and displaced thousands of people.

 Notley has assured that those with no homes to return to will be helped by the government.