Firefighters on Long Island were battling a wildfire on Sunday, one of several that forced the closure of sections of a highway in Suffolk County and prompted dozens of agencies to respond.

Four separate blazes erupted in the county on Saturday afternoon. By the evening, three had been extinguished and the fourth, in the Westhampton area, was 50 percent contained, Rudy Sunderman, the Suffolk County fire coordinator, said at a news conference on Saturday evening.

Two structures had been burned and one firefighter had been hospitalized with second-degree burns to the face, Ed Romaine, the Suffolk County executive, said at the news conference.

“We maximized our firefighting capabilities to stop this fire from spreading and then we tried to contain it,” Mr. Romaine said. “But it is not under control as I speak.”

Mr. Romaine added that he did not expect the Westhampton fire to be fully out until Sunday because there were high winds in the forecast.

Fire danger risk remained high on Long Island and in the Hudson Valley on Sunday, according to the New York State Department of Environmental Conservation. Although the humidity was forecast to be slightly higher than it had been on Saturday, wind gusts of up to 30 miles per hour were expected by the afternoon, the National Weather Service said.