In September, St Helens typically sees daytime highs of 16.9°C and overnight lows around 9.6°C. Compared to the annual average high of 12.6°C, September runs +4.3°C.
September in St Helens averages a daytime high of 16.9°C and an overnight low of 9.6°C.
September runs +4.3°C compared to St Helens's annual average high of 12.6°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 16.9°C and cooler evenings around 9.6°C.