Marty Ahrens from the NFPA Fire Analysis and Research department recently published the "Brush, Grass and Forest Fires" report. This report uses National Fire Incident Reporting Data from 2007-2011 and is a reflection on how often local (municipal or county) fire departments around the county are called to smaller brush, grass and forest fires. According to the report local fire departments responded to an estimated average of 334,200 brush, grass and forest fire per year. this translates to 915 such fires per day.
In three-quarters (76%) of the brush, grass, and forest fires handled by local fire departments, less than an acre burned. Only 4% burned more than ten acres. Fires in forests tended to be larger than other vegetation fires. Only three-fifths (59%) of the forest fires were less than an acre, while 9% consumed more than ten acres.