In September, Guelph typically sees daytime highs of 20.2°C and overnight lows around 8.7°C. Compared to the annual average high of 11.3°C, September runs +8.9°C.
September in Guelph averages a daytime high of 20.2°C and an overnight low of 8.7°C.
September runs +8.9°C compared to Guelph's annual average high of 11.3°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 20.2°C and cooler evenings around 8.7°C.