In August, Joliet typically sees daytime highs of 28.2°C and overnight lows around 16.2°C. Compared to the annual average high of 15.3°C, August runs +12.9°C.
August in Joliet averages a daytime high of 28.2°C and an overnight low of 16.2°C.
August runs +12.9°C compared to Joliet's annual average high of 15.3°C, ranking #2 of 12 months by warmth.
Plan for daytime highs near 28.2°C and cooler evenings around 16.2°C.