Issaquah (WA) Weather and Climate: A Comprehensive Guide
The temperature in Issaquah can vary quite a bit throughout the year.
Temperatures can be warm during the warmest months,
and cold during the cooler months.
It also has a relatively rain/snowy climate with high levels of precipitation.
Let’s explore the climate details in depth to provide you with a complete overview.
Average maximum day and minimum night temperature
Visitors to Issaquah can expect significant temperature changes throughout the year. On average, daytime temperatures range from a comfortable 24°C in July to a chilly 6°C in December.
Nighttime temperatures can drop, with average lows reaching 1°C in December. Check out our detailed temperature page for more information.Temperature ranges by month
Precipitation and rainy days
Issaquah is known for its substantial rain/snowfall, with annual precipitation reaching 1573 mm. The seasons in Issaquah, bring significant changes in precipitation. The wettest month, November, receives heavy rainfall, with an average of 237 mm of precipitation. This rainfall is distributed across 23 rainy days. In contrast, the driest month, July, experiences much less rainfall, totaling 25 mm 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 over the year
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
Average humidity
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%. Explore our detailed page on humidity levels for further details.
Relative humidity over the year
Average wind speed
The average wind speed over the year ranges from 4 m/s to 5 m/s. It is lower in February, April, May, June, July, August, September, October, November and December and higher in January and March.
The mean monthly wind speed over the year (meters per second)
overcast and heavy rain broken clouds and rain broken clouds and rainForecast for Issaquah (WA)
3 m/s
5 m/s
3 m/s
The best time of year to visit Issaquah in the United States of America
During the months of July, August and September you are most likely to experience good weather with pleasant average temperatures that fall between 20°C and 26°C.Other facts from our historical weather data:
Most rainfall (rainy season) is seen in January, March, November and December.
July has an average maximum temperature of 24°C and is the warmest month of the year.
The coldest month is December with an average maximum temperature of 6°C.
November tops the wettest month list with 237 mm of rainfall.
July is the driest month with 25 mm of precipitation.
July is the sunniest month with an average of 312 hours of sunshine.
No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.
