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Hourly Forecast
Daylight Hours
06:52
Sunrise
19:12
Sunset
Moon
Waxing Crescent
12:17
Moonrise
20:25
Moonset
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Weather in Issaquah today, September 15, 2026
Expect a mostly clear day in Issaquah on September 15, 2026, with sunshine dominating from morning through evening. Cloud should stay limited, so the overall feel remains bright and settled. Expect a grey start, with morning cloud around 100% by 11:00. Outdoor plans early on should not rely on bright skies.
Temperatures climb from an overnight low near 13°C toward a daytime high of about 20°C. Moisture in the air spans 55%-85%, with the highest values around 08:00. Winds stay light, near 3.6 km/h by 17:00, so the day feels still more than breezy.
Expect persistent cloud later on, with amounts around 66% by 12:00. Sunshine remains the exception, not the rule. Views remain open at about 16.1 km. The sun rises at 06:52 and sets at 19:12, for a total of 12 hours 19 minutes of sunlight today.
Overall, Issaquah on September 15, 2026 favours outdoor plans under mostly open skies, with a comfortable high near 20°C.
Frequently asked questions about weather in Issaquah
How warm does it get in Issaquah?
The warmest month in Issaquah is August, with average high temperatures of 25°C. The average temperature during this period is around 18°C.
How cold does it get in Issaquah?
The coldest month in Issaquah is February, with average low temperatures of 2°C. The average temperature during this period is around 4°C.
What is the wettest time of year in Issaquah?
The wettest month in Issaquah is December, with an average of 246mm of precipitation.
What is the driest time of year in Issaquah?
The driest month in Issaquah is July, with an average of 25mm of precipitation.
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