Giant red zone: Fire danger extreme across Saskatchewan, Alberta

As tens of thousands ofresidentsflee from FortMcMurray,Alta., the threat of more fires continuestoloomacross Alberta and Saskatchewan.

• RELATED:'Catastrophic' Fort McMurray wildfire prompts state of emergency

On May 4, Natural Resources Canada indicated that the risk of fire is "extreme" in the two provinces.

A map the federal department produced for Wednesday shows a huge red zone over most of the region.

The CanadianWildlandFire Information System is a computer-based system that monitors fire danger conditions across Canada.

The system creates a fire danger map based on daily weather conditions such as temperature and humidity.

It also takes into considerationfactors like how easy it is to ignite vegetation, how difficult a fire may be to control, and how much damage a fire can do.

1 week ago

Last week, fire danger was rated as "low" in places now consumed by fire, like FortMcMurray.

In Saskatchewan, there was virtually nowhere in the "extreme" risk zone.

This time last year

On May 4, 2015, the fire danger map indicatedvarying risk levels, with the majority of the provinces sitting at "low" to "moderate" risk.

In Saskatchewan, the "extreme" risk zone was limited to the extreme southwest and southern regions. This was before a record-breaking summer in Saskatchewan for wildfires.

In 2015, the flames and smoke forced more than13,000 people from their homes in northern Saskatchewan, making it the largest evacuation in province'shistory. The total area burned by wildfires in 2015 was 1,719,090 hectares.