In September, Stevenage typically sees daytime highs of 18.2°C and overnight lows around 10.3°C. Compared to the annual average high of 13.3°C, September runs +4.9°C.
September in Stevenage averages a daytime high of 18.2°C and an overnight low of 10.3°C.
September runs +4.9°C compared to Stevenage's annual average high of 13.3°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 18.2°C and cooler evenings around 10.3°C.