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: 3915 (Low) Fri, 15 May 2026 08:00:04 http://pollenandmold.stlouisco.com/Default.aspx http://pollenandmold.stlouisco.com/Default.aspx Air Quality for 5/15/2026: Yellow