Central Ohio's unemployment rate for June is 4.2 percent, an increase of two-tenths of a point from May. The Ohio Department of Job and family services says the unemployment rate rose in 78 of Ohio's 88 counties in June because of increased demand by students seeking summer jobs. Delaware County had the lowest rate in the region at 3.6 percent followed by Union County at 3.9 percent and Madison County at 4 percent. The rate for Columbus and Franklin County matched the regional rate. The department says the overall state jobless rate is 5.2 percent.