In February, O'Fallon typically sees daytime highs of 6.6°C and overnight lows around -4.6°C. Compared to the annual average high of 18.9°C, February runs -12.2°C.
February in O'Fallon averages a daytime high of 6.6°C and an overnight low of -4.6°C.
February runs -12.2°C compared to O'Fallon's annual average high of 18.9°C, ranking #10 of 12 months by warmth.
Plan for daytime highs near 6.6°C and cooler evenings around -4.6°C.