What to Wear in Seattle in September
Mild early autumn. Expect 12°–22°C with 6 rainy days on average.
☀️
High
22°C
🌙
Low
12°C
🌧️
Rain days
6
🌡️
Feel
Mild & Comfortable
Typical outfit
~17°C average
About September in Seattle
September in Seattle typically brings mild early autumn. With averages of 12°–22°C, the conditions call for ideal sightseeing weather! layer smartly — mornings and evenings will be cooler.
Mornings feel cool but afternoons can warm up significantly. A trench or jacket over a lighter outfit is ideal.
September in other cities