ST. JOHNS COUNTY, Fla. -

Temperatures are scorching in northeast Florida, and there's no substantial rain in sight, which combines for extreme fire conditions.

Firefighters in Flagler County still don't know what caused a wildfire there that has burned more than 400 acres in the Espanola area. And In St. Johns County, fire crews were mopping up hot spots in a brush fire that temporarily closed State Road 207 on Tuesday.

There are 25 active wildfires burning in Duval, Nassau, Clay, Baker and St. Johns counties. Most of the fires are relatively small, but at least three are more than 100 acres.

There are 256 active wildfires burning statewide.

Since Jan. 1, more than 2,400 wildfires have burned, charring 850,000 acres across Florida.

Burn bans have been imposed in Alachua, Baker, Flagler, Nassau, Putnam, St Johns, Union and Volusia counties. It has always been illegal to burn outdoors in Duval County, which is why it hasn't enacted a ban this fire season.

Firefighters said it may take a tropical storm to bring the drought numbers down.

"I think that's one of the biggest misconceptions that people have is that, 'Hey, we get a thunderstorm or a nice rainstorm one afternoon and we're good to go. Things are cleaned up now. The fires aren't going to be as bad," St. Johns County Fire Rescue spokesman Jeremy Robshaw said. "The reality of it is, we need a consistent stretch of rain every afternoon, some heavy rain, maybe a tropical system of some sort that comes through our general area and gives us that really soaking rain. That's the only thing that's going to make a difference."

Florida Division of Forestry officials are warning residents to be cautious in preventing wildfires from starting. They said current wildfire conditions are so critical that even the smallest spark could ignite a raging wildfire.

For more information and safety tips on preventing fires from spreading, go to Firewise.org.