In September, Knoxville typically sees daytime highs of 27.7°C and overnight lows around 15.3°C. Compared to the annual average high of 20.6°C, September runs +7.2°C.
September in Knoxville averages a daytime high of 27.7°C and an overnight low of 15.3°C.
September runs +7.2°C compared to Knoxville's annual average high of 20.6°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 27.7°C and cooler evenings around 15.3°C.