Hennepin is located in north Illinois. Hennepin is part of Putnam County. Hennepin has 5.26 square miles of land area and 0.37 square miles of water area. As of 2010-2014, the total Hennepin population is 979, which has grown 38.47% since 2000. The population growth rate is much higher than the state average rate of 3.62% and is much higher than the national average rate of 11.61%. Hennepin median household income is $54,844 in 2010-2014 and has grown by 17.12% since 2000. The income growth rate is lower than the state average rate of 22.70% and is much lower than the national average rate of 27.36%. Hennepin median house value is $123,500 in 2010-2014 and has grown by 31.80% since 2000. The house value growth rate is lower than the state average rate of 34.33% and is lower than the national average rate of 46.91%. As a reference, the national Consumer Price Index (CPI) inflation rate for the same period is 26.63%. On average, the public school district that covers Hennepin is close to the state average in quality. The Hennepin area code is 815.