 In recent years, average temperatures in the county seat of McLeansboro have ranged from a low of in January to a high of in July, although a record low of was recorded in January 1930 and a record high of was recorded in July 1936.Average monthly precipitation ranged from in February to in May.As of the 2010 United States Census, there were 8,457 people, 3,489 households, and 2,376 families residing in the county.