You might spend a lot of your holiday inside, but if you're planning to venture beyond the casino, taking a look at local weather data can help you. The hottest months are usually August and July, with an average temperature of 16°C, while the coldest months are December and February, with an average of 3°C. The rainiest months in Snoqualmie are November, January, December and October, with each month seeing an average of 252 mm of rainfall.