The unemployment rate in central Ohio fell to 3.9 percent in August, down a tenth of a point from July. The Ohio Department of Job and Family Services says this is the only region that had a rate below 4 percent last month. Jobless rates fell or held steady in all metropolitan areas and all but one of the state's 88 counties, as summer jobs for students ended. Delaware County had an unemployment rate of 3.4 percent and Madison and Union counties had rates of 3.5 percent.