EDMONTON - Faced with raging wildfires and more hot, dry weather, the Alberta government is urging people to be careful if they plan to play outside in the coming days.

"One can only hope that the Alberta tradition of a cold and wet May long weekend will reappear," Premier Rachel Notley said Monday. "The fact is that most of Alberta remains under conditions of extreme fire risk."

The province issued a fire weather advisory for some areas warning that wildfires will become large quickly and tough to control.

The government has banned campfires and other open fires over the northern half of the province from the Red Deer area to the Northwest Territories boundary.

There is also a ban on the recreational use of off-highway vehicles on public land in the same area over concerns they could spark fires in tinder-dry forests and brush.

Notley warned that even a carelessly tossed cigarette butt could cause trouble.

"I would like to remind all Albertans that we have a fire ban across much of Alberta for a reason. We have a ban on recreational use of off-highway vehicles across much of the province for a reason," she said.

On Monday the wildfire that forced more than 80,000 people from Fort McMurray last week had grown to more than 2,800 square kilometres. It was burning away from the city but there are concerns about hot spots reigniting.

Another fire in the Municipal District of Greenview forced the mandatory evacuation of farms and rural homes in a region northwest of Edmonton.

The province said more than 1,900 firefighters were battling the fires, including crews from B.C., Ontario, Saskatchewan and Nova Scotia with more on the way.

Wildfire officer Barry Shellian said even if Alberta gets some rain and cooler temperatures later this week it won't be enough to make a difference.

He said the forest and grasslands are particularly parched this year due to lack of rain and less snow than usual over the winter.

The province is also warning boaters planning to head out on lakes to be mindful of the water bombers that are fighting fires in the Fort McMurray area and in other parts of the province.

Shellian said these aircraft may need to drop down for another load of water to dump on the flames.

"If boaters or recreationalists see planes circling we want them to remove themselves from the lake to ensure that these planes can be effective and safe," he said.

News from © The Canadian Press, 2016