In September, Saint-Hyacinthe typically sees daytime highs of 19.7°C and overnight lows around 8.8°C. Compared to the annual average high of 10.8°C, September runs +8.8°C.
September in Saint-Hyacinthe averages a daytime high of 19.7°C and an overnight low of 8.8°C.
September runs +8.8°C compared to Saint-Hyacinthe's annual average high of 10.8°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 19.7°C and cooler evenings around 8.8°C.