In March, Saint Charles typically sees daytime highs of 12.1°C and overnight lows around 0.3°C. Compared to the annual average high of 18.7°C, March runs -6.6°C.
March in Saint Charles averages a daytime high of 12.1°C and an overnight low of 0.3°C.
March runs -6.6°C compared to Saint Charles's annual average high of 18.7°C, ranking #9 of 12 months by warmth.
Plan for daytime highs near 12.1°C and cooler evenings around 0.3°C.