Summer taxes are usually due by September. Winter taxes are due by February 28. All taxes become delinquent to the County Treasurer on March 1 with additional penalties and interest, computed with a 4% penalty, and 1% interest per month for the first year. Taxes that are delinquent more than a year will have a substantially higher interest rate (1.5% instead of 1%). In addition, a $175.00 forfeiture fee will be added along with additional administrative fees.