Average temperatures, rainfall and packing tips for Seattle, United States in September
🌡️ Avg high
21°C
🌙 Avg low
13°C
🌧️ Rainfall
~39 mm
📊 Warmth rank
#3 of 12
September in Seattle at a glance
September in Seattle is typically warm, with average daytime highs around 21°C and nights near 13°C. It is one of the warmer months of Seattle's year.
Expect some rain: around 39 mm falls in Seattle during September on average.
What to pack for Seattle in September
T-shirts and light layers
A light jacket or sweater for the evenings
Seattle - year at a glance
HighLow · September highlighted
Is September a good time to visit Seattle?
🧳 September is one of the most comfortable months to visit Seattle - daytime temperatures sit in a pleasant range and it's a good pick for sightseeing and time outdoors.
In September, Seattle averages a daytime high of about 21°C and a night-time low of around 13°C, based on recent historical data.
Does it rain in Seattle in September?
Expect some rain: around 39 mm falls in Seattle during September on average.
Is September a good time to visit Seattle?
September is one of the most comfortable months to visit Seattle - daytime temperatures sit in a pleasant range and it's a good pick for sightseeing and time outdoors.