At least 9 million people in the nation's upper Midwest region are under red flag warnings on Monday, including residents of Minnesota, where a wildfire was already burning out of control in the largest national forest east of the Mississippi River.

Potentially record-high temperatures, wind gusts of up to 45 mph, low relative humidity and dry conditions are elevating the risk of wildfires spreading quickly across a large swath of the upper Midwest. Red flag warnings signaling wildfire danger have been issued for parts of Wisconsin, North Dakota, South Dakota, Nebraska, Montana and nearly the entire state of Minnesota.

As red flag warnings were issued, firefighters in Minnesota continued to battle the Camphouse Fire in the Superior National Forest near Brimson, about 40 miles north of Duluth. According to the Minnesota Interagency Fire Center, the Camphouse Fire, which started Sunday afternoon, grew overnight to more than 750 acres and was 0% contained.

St. Louis County Sheriff Gordon Ramsey said at a Sunday night news conference that at least 20 residents in the area were evacuated. Ramsey said no injuries have been reported.

Making matters worse for firefighters were high temperatures forecast for most of Minnesota. Temperatures in the Duluth area are expected to reach the 80s on Monday.