Unemployment Rate in St. Charles County, MO was 3.00% in May of 2026, according to the United States Federal Reserve. Historically, Unemployment Rate in St. Charles County, MO reached a record high of 10.70 in April of 2020 and a record low of 1.50 in October of 1999. Trading Economics provides the current actual value, an historical data chart and related indicators for Unemployment Rate in St. Charles County, MO - last updated from the United States Federal Reserve on July of 2026.