ROANOKE COUNTY, Va. -

Fire departments across the region are closely watching for brush fires.

Roanoke Fire and EMS have put out two along Interstate 581 in less than a week.

While we are waiting to find out what caused those fires, firefighters have a warning for people in the coming weeks.

Fire officers told WDBJ7 that the sudden change in weather is not helping.

The most recent brush fire along I-581 started Monday afternoon near Elm Avenue and Wonju Street.

Firefighters were forced to shut down part of the roadway while they put it out. Roanoke County Fire and EMS said despite all of the wet weather we've seen with the rain and snow, it only takes one humid day to dry out the surface.

Those conditions are ideal for a fire to start and spread. They said the biggest factors that play a role in these types of brush fires are wind, temperature and humidity.

"On those days when all those three factors, if you will, the perfect storm, then certainly we are at a little more awareness level then we are when its low temperatures, low wind, high humidity,” said Roanoke County Fire & Rescue Chief Richard E. Burch Jr.

A spokeswoman with the Roanoke City Fire Department said they expect to see an uptick in mulch fires because of these warmer conditions.

Burch said the county is already seeing an increase.

Right now, the state has a burn ban in place that says no burning before 4 p.m. during this time of year.

If you live in the county and wish to burn, you must apply for a permit. There are only rural areas where burning is allowed within county and state guidelines.