Issaquah (WA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Issaquah.
Climate overview of Issaquah
Issaquah, Washington State, United States of America, sees big temperature differences between seasons, with July peaking at 24°C (75°F) and December dropping to 6°C (43°F).
The city has a wet climate, receiving around 1573 mm (62 in) of rain/snowfall per year. Despite the high annual total, it has distinct dry (July to August) and wet (November to January) seasons. November is the wettest month. Sunshine peaks in July, when the city sees around 10.4 hours of sunshine per day.
Issaquah Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Issaquah — and find the best time to visit.
Monthly Temperature in Issaquah
Visitors to Issaquah can expect significant temperature changes throughout the year. On average, daytime temperatures range from a comfortable 24°C (75°F) in July to a chilly 6°C (43°F) in December.
Nighttime temperatures range from 13°C (55°F) in July to 1°C (34°F) in December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Issaquah
Issaquah is known for its substantial rain/snowfall, with annual precipitation reaching 1573 mm (62 in). The seasons in Issaquah bring significant changes in precipitation. The wettest month, November, receives heavy rainfall, with an average of 237 mm (9.3 in) of precipitation. This rainfall is distributed across 23 rainy days.
In contrast, the driest month, July, experiences much less rainfall, totaling 25 mm (1 in) over 6 rainy days. These distinct seasonal differences provide diverse experiences throughout the year. For more details, please visit our Issaquah Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Issaquah
In Issaquah, summer days are longer and more sunny, with daily sunshine hours peaking at 10.4 hours in July. As the darker season arrives, the brightness of the sun becomes less. December sees a soft sun for only 1.8 hours per average day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Issaquah by Month
The relative humidity is high throughout the year in Issaquah.
The city experiences its highest humidity in December, reaching 80%. In July, the humidity drops to its lowest level at 65%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Wind Speed in Issaquah
The average wind speed over the year ranges from 4 m/s (8 knots) to 5 m/s (10 knots). It is lower in February, April, May, June, July, August, September, October, November and December and higher in January and March. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit Issaquah
The weather does bring rainfall during this period, between 25 mm (1 in) and 85 mm (3.3 in).
Plan accordingly for January, March, November and December, when conditions bring the heaviest precipitation. Need help choosing your next travel destination? We offer a specialized tool that matches you with locations based on your weather preferences. Explore destinations that suit your climate preferences.
Frequently asked questions about the climate in Issaquah
What is the best time to visit Issaquah?
June, July, August and September typically offer the most optimal weather in Issaquah. In contrast, January, February, March, April, November and December tend to have less optimal conditions. Issaquah has distinct dry (July to August) and wet (November to January) seasons.
What temperatures can I expect in Issaquah?
Daytime highs range from 6°C (43°F) in December to 24°C (75°F) in July. Nighttime lows range from 1°C (34°F) to 13°C (55°F). Temperatures vary considerably through the year.
How much rain does Issaquah get?
Annual rainfall is around 1573 mm (62 in). November is the wettest month with 237 mm (9.3 in), while July is the driest with 25 mm (1 in).
How sunny is Issaquah?
Issaquah receives around 2,171 hours of sunshine per year. July is the sunniest month with 312 hours, while December is the cloudiest with just 54 hours. Overall, Issaquah enjoys abundant sunshine.
Issaquah 3-Day Forecast
Issaquah (WA) 3-Day Forecast
Issaquah on the map
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