In September, London typically sees daytime highs of 21.5°C and overnight lows around 10.2°C. Compared to the annual average high of 12.6°C, September runs +8.9°C.
September in London averages a daytime high of 21.5°C and an overnight low of 10.2°C.
September runs +8.9°C compared to London's annual average high of 12.6°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 21.5°C and cooler evenings around 10.2°C.