Clinton County, Ohio

Clinton County is a county located in the U.S. state of Ohio. As of the 2020 United States census, the population was 42,018. Its county seat and largest city is Wilmington. The county is named for former U.S. Vice President George Clinton. Clinton County comprises the Wilmington, Ohio Micropolitan Statistical Area, which is also included in the Cincinnati-Wilmington-Maysville, OH-KY-IN Combined Statistical Area.

Clinton County was formed on February 19, 1810, from sections of Highland County and Warren County, with the law creating the county taking effect on March 1 of that year. It was named after George Clinton, a soldier, politician, Governor of New York, and Vice President of the United States.

According to the U.S. Census Bureau, the county has a total area of 412 square miles (1,070 km²), of which 409 square miles (1,060 km²) is land and 3.6 square miles (9.3 km²) (0.9%) is water.

The entire county lies within the Little Miami River watershed, with the exception of extreme eastern areas, which are within the Scioto River watershed. Clinton County lies within the till plains physiographic region, and is somewhat flat or gently rolling. The northern two thirds of the county were covered with an ice sheet during the Wisconsinan Stage, while the southern third was covered by ice sheets during the much older Illinoian Stage. Because of such a history with ice, glacial features are readily found on the landscape, such as moraines and kames.

The general elevation of the county is roughly 1,050 feet (320 m) above sea level, and there are few areas in the county that deviate from this by more than 200 feet (61 m).

The climate of Clinton County can be classified as humid continental. It is one of the coolest and wettest counties in southern Ohio, although differences between it and other southern Ohio counties are usually very slight. Clinton County averages 42 inches (1.1 m) of precipitation per year, including 30 inches (0.76 m) of snow (Note: one inch of snow does not equal one inch of precipitation). Average July high temperatures reach the mid and upper 80s F although temperatures above 90 F are common, while lows are typically in the 60s F. January high temperatures typically reach the low and mid 30s F, while lows generally bottom out in the 10s F, although lows in the single digits and even below 0 °F or −17.8 °C are common.

Adjacent counties

As of the 2010 United States census, there were 42,040 people, 16,210 households, and 11,364 families living in the county. The population density was 102.9 inhabitants per square mile (39.7/km²). There were 18,133 housing units at an average density of 44.4 per square mile (17.1/km²). The racial makeup of the county was 94.7% white, 2.2% black or African American, 0.5% Asian, 0.2% American Indian, 0.5% from other races, and 1.9% from two or more races. Those of Hispanic or Latino origin made up 1.3% of the population. In terms of ancestry, 26.4% were German, 15.4% were Irish, 12.0% were American, and 11.9% were English.