Will I be cold?
Will I be cold in London in September?
Verdict
Maybe — Chilly at times.
Lows near 52°F — cool mornings and evenings, comfortable afternoons.
Day vs. night
Day
66°F
Comfortable
A T-shirt and a light overshirt is enough.
Night
52°F
Cool
You'll want a warm layer after sunset — not a heavy coat.
Why
London in September averages highs of 66°F, lows of 52°F, 9 rainy days.
Layering wins here. A packable puffer plus a base layer handles the cool end without overheating in the middle of the day.
See a full outfit plan for chilly evenings →
London in September outfit ideas from ForecastStyle.