Verdict: Excellent month
Basel Weather in September
September hits the sweet spot in Basel — highs around 22°C (72°F), ideal for a full day on foot. Expect showers on roughly 11 days of the month — rarely trip-ruining, worth planning around. Overall, September is one of the best months of the year to be in Basel.
Average high
22°C / 72°F
Average low
12°C / 54°F
Rain days
~11
Precipitation
85 mm
What to pack for Basel in September
- Summer clothes, plus one light layer for air-con and evenings
- A packable rain shell or compact umbrella earns its space
- Comfortable walking shoes — every guide on this site assumes you'll use them
September against the rest of the year
Warmest in Basel: Jul (26°C / 79°F) · Coolest: Jan (6°C / 43°F) · Wettest: Dec (~16 rain days)
6°
-1°
Jan
10°
1°
Feb
12°
2°
Mar
15°
5°
Apr
19°
9°
May
24°
14°
Jun
26°
15°
Jul
26°
16°
Aug
22°
12°
Sep
17°
8°
Oct
10°
3°
Nov
7°
1°
Dec
Daily highs / lows in °C · bars show rain days per month · ERA5 climate normals (2020–2024)