NAHUNTA, Ga. (AP) — Wildfires burning across the southeastern U.S. were intensifying Wednesday after destroying nearly 50 homes in Georgia and forcing evacuations and school closures in some communities.

Some of the biggest blazes were along Georgia’s coast and between and around Jacksonville, Florida, a state that is facing one of its worst fire seasons in decades. It was not yet clear how the wildfires started, but a long drought, low humidity and strong winds were fueling them.

Georgia’s two biggest wildfires together have burned more than 31 square miles, with at least four other smaller fires reported. The area of the state where the worst fires were burning is experiencing extreme drought, according to the U.S. Drought Monitor.

In southeast Georgia, the fast-moving Brantley County fire was threatening more homes Wednesday after destroying 47 a day earlier. That fire grew in size by six times in just half a day.

Brantley County Sheriff Len Davis warned residents to be ready to evacuate, given that winds could change rapidly. About 800 evacuations have taken place, and five shelters have opened, as the fire threatens 300 more homes.

In Florida, firefighters were battling 131 wildfires that had burned 34 square miles, mostly in the state’s northern half. Firefighting resources are being mobilized across the state due to the challenging conditions.

Air quality has been impacted in cities like Atlanta and Jacksonville, with unhealthy smoke levels reported in certain areas. The high fire risk is predicted to continue due to persistent dry weather.

The situation remains critical, with authorities urging all residents in affected areas to remain vigilant and prepared for potential evacuations.