In September, Waterloo typically sees daytime highs of 23.8°C and overnight lows around 10.3°C. Compared to the annual average high of 14.4°C, September runs +9.4°C.
September in Waterloo averages a daytime high of 23.8°C and an overnight low of 10.3°C.
September runs +9.4°C compared to Waterloo's annual average high of 14.4°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 23.8°C and cooler evenings around 10.3°C.