The month in detail
What to expect in September
Autumn in Seattle is often underrated: 68°F, golden light and declining crowds. An interesting window. Rain risk remains low (24% of days), leaving good room for outdoor activities. A good balance between weather and crowds, even if July (8.9/10) remains theoretically better.
September ranks 4 out of 12 months in Seattle. Compared to August: −7°F daytime, 11 pts more rainy days, −1.7h of sun per day.
This month's conditions
What it's like in September
UV index
4 · moderate
protect during midday hours
Feels like
comfortable
12°
Daylight
12.3h of daylight
Air quality
good
AQI 25
Compare
Is September the right month?
The best month in Seattle is July (8.9/10), 1.2 pt higher than September.
Book
Plan your trip
Hotels at their lowest outside peak season, highest on comfortable months. Shoulder seasons offer a good price/climate compromise.
Stay
Hotels & rentals · Seattle
Expedia →
Activities
Tours, tickets, experiences
See ↓
Flights
Multi-airline comparator
Kiwi →
🎟️ Activities & tours · Seattle
GetYourGuide selection · free cancellation
Practical info
What you need to know before you go
Three angles: the country (language, currency, safety, budget), the year-round climate, and the specifics of a beach trip.
Country · USA
🗣️LanguageEnglish
💶CurrencyUS Dollar ($)
🚗DrivingRight-hand
🛡️Safety ⓘVery safe · 1/5
💰Cost of living ⓘExpensive · 4/5
🌡️ Climate
🌍Climate typeTemperate oceanic
📈Climate trend ⓘStable
🔥Hottest monthJuly · 75°F
❄️Coolest monthJanuary · 46°F
🌧️Rainiest month ⓘDecember · 46%
🏖️ Beach trip
📅Peak seasonJuin → Sept
🏖️Swell (Sept–Mar) ⓘModérée
Explore
Other destinations in September
If September doesn't convince you for this destination, compare with others.
Location
Where is Seattle ?
Global position + regional geographic context.
🌍 World
🔍 Geographic context
USATemperate oceanic climate with a 8.9 → 0.8 gap between best and worst month. 10 years of ERA5 data to choose by project.
47.61°N · 122.33°W
Questions
Frequently asked questions
What is the best time to visit Seattle?
July is the best month with 75°F highs, 57°F lows, 10.1h of sunshine and 9.0% rainy days. The months of July & August offer comparable conditions.
How many hours of sunshine does Seattle get in July?
Seattle averages 10.1 sunshine hours per day in July. It is the sunniest month with a climate score of 8.5/10.
What is the rainiest month in Seattle?
January is the most unfavourable month with January has the lowest climate score of the year and the lowest climate score of the year.
What are the temperatures at night in Seattle in July?
In July, overnight lows reach 57°F, while afternoon highs average 75°F.
Is Seattle good in winter?
In winter (December-February), Seattle scores 0.9/10 on average — Difficult period — prefer the peak season.. The best month overall remains July with a score of 8.5/10.
When should you avoid Seattle?
January is the most difficult month to visit Seattle, with January has the lowest climate score of the year. Climate conditions are at their lowest of the year during this period.
Do you need sun protection in Seattle in September?
The average UV index reaches 4 in September in Seattle (moderate), with about 12.3h of daylight. Protect during midday hours.