The National Weather Service has extended its red flag warning to El Paso County, which joins Fremont County and the San Luis Valley to the south in the warning area.

The warning is set to expire at 7 p.m. Sunday, according to the National Weather Service.

Westerly winds gusting up to 35 mph and relative humidity readings below 7 percent could cause any fire to spread quickly and grow out of control, the service stated. A red flag warning means weather conditions are ripe for fast-spreading fires.