Anastasia Drummond, a wildfire information officer with Alberta Sustainable Development, says more than 23,000 hectares have burned in 861 wildfires since April 1.Anastasia Drummond, a wildfire information officer with Alberta Sustainable Development, says more than 23,000 hectares have burned in 861 wildfires since April 1. (CBC)Hot, dry weather has sparked wildfires, causing partial highway closures and fire bans in a dozen provincial parks in Alberta.

Thousands of lightning strikes, combined with dry timber and low humidity, contributed to about 170 new fires on the weekend, a provincial official said Monday.

One of the fires near Grayling Creek and Gregoire Tower, about 45 kilometres south of Fort McMurray, closed part of Highway 63 to Fort McMurray. Traffic has been detoured to Highway 881, with traffic being redirected at the junctions of highways 63 and 881, highways 55 and 63 and highways 55 and 36. Officials now estimate the fire is about 2,000 hectares in size.

Late Monday afternoon, officials with the Regional Municipality of Wood Buffalo said a separate wildfire 80 kilometres north of Lac la Biche could cross Highway 881 later in the evening and smoke could force the closure of the highway.

Although most of the weekend fires were extinguished or contained, 22 remain out of control.

"They are located north of Edmonton in the Slave Lake, Lac La Biche, Fort McMurray, Peace River, Whitecourt areas," said Anastasia Drummond, a Wildfire Information Officer for Alberta Sustainable Development.

"As of this afternoon, we have actioned over 861 wildfires since April 1. That's a 20 per cent increase over the five-year-average for today's date."

The province now has 480 firefighters, 22 tankers and 65 helicopters fighting 72 wildfires that have burned more than 23,000 hectares.

Meanwhile, the province placed a fire ban on 12 provincial parks and recreation areas Monday, suspecting campfires as the cause of three small fires during the weekend.

Fire hazards range from moderate in southern Alberta to high in the northern regions, said Drummond.

"The further north and east you go, the hazard is climbing," she said. "Each consecutive day we don't see organized rainfall, that hazard will continue to climb."

On Sunday evening, Alberta requested 175 firefighters from other provinces and territories via the Canadian Interagency Forest Fire Centre in Manitoba. Some of those resources are expected to arrive by Wednesday.