London · September
Run in the morning.
Cool month: average high 68°F, low 53°F. Humidity averages 78% — the limiting factor on most runs. Cool, runnable conditions throughout — morning still has the steadiest air and lightest wind.
Avg high / low
68° / 53°F
Humidity
78%
Rain days
13/mo
Wind
12 mph
What September feels like in London
Sunrise
06:36
Mid-month average
Sunset
19:14
Mid-month average
Time-of-day breakdown
Morning
Coolest, driest air of the day. The window before sunrise is the most reliable comfortable hour.
Midday
Mild but UV and traffic peak. Workable if you don't mind shifting your pace.
Evening
Warm and runnable. Crowded routes but the air's typically calm.
What to wear running in London in September
The kit for September in London: shorts and a short-sleeve are the standard kit, a water-resistant cap or jacket on standby.
September vs the surrounding months
vs August
-4° avg high
-3 rain days
London in August →
September
68°F avg high
13 rain days
Best: morning
vs October
+8° avg high
-3 rain days
London in October →
Frequently Asked Questions
What is the best time of day to run in London in September?+
Morning. Cool, runnable conditions throughout — morning still has the steadiest air and lightest wind.
What's the average temperature in London in September?+
Average high 68°F, average low 53°F.
How does September compare to surrounding months in London?+
Compared to August (avg high 72°F), September is cooler. Compared to October (avg high 60°F), September is warmer.
Does it rain often in London in September?+
Expect about 13 measurable rain days in September, on average.