Vancouver vs Seattle

Vancouver and Seattle are closely matched in September. Neither city has a clear advantage across all metrics. Your decision should come down to personal preference, cultural interests, and travel logistics rather than weather alone.

Vancouver sits in the comfortable travel range at 20°C. Seattle is also comfortable at 22°C.

For travelers who prioritize dry weather, Seattle is the stronger choice in September. Vancouver receives 6 more hours of sunshine per day, which matters for sightseeing and outdoor activities.

Vancouver reaches an average high of 20°C (68°F) and drops to 13°C (55°F) at night during September. The daily temperature range is 7°C, meaning relatively stable temperatures from day to night.

Seattle averages 22°C (72°F) for the high and 13°C (55°F) for the low, with a daily range of 9°C. The 2°C difference is noticeable but not dramatic.

Both cities are in the Northern Hemisphere, so they share the same seasonal pattern in September.

Vancouver receives approximately 117 mm of rainfall across 10 rain days during September. You can expect rain roughly every other day.

Seattle sees 45 mm over 4 rain days. That makes Seattle the drier option by 6 rain days and 72 mm of total precipitation.

Both cities share similar humidity levels at 65%.