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Issaquah, WA Weather


Issaquah, WA climate is mild during summer when temperatures tend to be in the 60's and cold during winter when temperatures tend to be in the 40's.

The warmest month of the year is August with an average maximum temperature of 75.20 degrees Fahrenheit, while the coldest month of the year is January with an average minimum temperature of 33.10 degrees Fahrenheit.

Temperature variations between night and day tend to be moderate during summer with a difference that can reach 23 degrees Fahrenheit, and fairly limited during winter with an average difference of 14 degrees Fahrenheit.

The annual average precipitation at Issaquah is 62.06 Inches. Winter months tend to be wetter than summer months. The wettest month of the year is November with an average rainfall of 9.43 Inches.

Weather Data

Normal Climate

Normal Temperatures

(SNOQUALMIE FALLS Weather station, 9.50 miles from Issaquah)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Max °F 45.7 49.5 53.2 58.2 63.7 68.3 74.2 75.2 70.0 60.0 50.3 45.0 59.4
Mean °F 39.4 41.8 44.3 48.4 53.8 58.5 63.1 63.7 58.6 50.8 43.9 39.4 50.5
Min °F 33.1 34.1 35.4 38.5 43.9 48.6 52.0 52.1 47.1 41.6 37.4 33.8 41.5

Normal Precipitation

(SNOQUALMIE FALLS Weather station, 9.50 miles from Issaquah)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Inch 8.45 6.46 6.18 4.63 3.79 2.94 1.60 1.50 2.80 5.26 9.43 9.02 62.06