Saint Louis County Department of Health - Pollen and Mold Center Pollen and Mold Center. Saint Louis County, Missouri: Aeroallergen Reports Saturday Sunday 11 10 9 8 7 6 5 4 3 2 1 0 Mold Count: 26843 (High) Fri, 18 Sep 2026 08:55:21 http://pollenandmold.stlouisco.com/Default.aspx http://pollenandmold.stlouisco.com/Default.aspx Air Quality for 9/18/2026: Orange