ClimateForecastNovemberDecember >>

Issaquah (WA) Climate by Month

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 day and 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 averages reaching 1°C in December.

The mean minimum and maximum temperatures throughout the year

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.

The mean monthly precipitation over the year, including rain, hail and snow

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.

Monthly hours of sunshine

Data from: Seattle, the United States of America (21 KM, 13 Miles).

Daily hours of sunshine

Data from: Seattle, the United States of America (21 KM, 13 Miles).

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:
  • Which months have the greatest rainfall in Issaquah?
    Most rainfall (rainy season) is seen in January, March, November and December.
  • Which is the warmest month in Issaquah?
    July has an average maximum temperature of 24°C and is the warmest month of the year.
  • Which is the coldest month in Issaquah?
    The coldest month is December with an average maximum temperature of 6°C.
  • Which is the wettest month in Issaquah?
    November tops the wettest month list with 237 mm of rainfall.
  • Which is the driest month in Issaquah?
    July is the driest month with 25 mm of precipitation.
  • Which is the sunniest month in Issaquah?
    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.

    Forecast for Issaquah (WA)

    Sat   Nov 23
    12°C | 5°C
    SW 11 km/h
    2.1 mm
    broken clouds and  chance of rain

    broken clouds and chance of rain

    Sun   Nov 24
    9°C | 5°C
    SE 7 km/h
    17 mm
    overcast and heavy rain

    overcast and heavy rain

    Mon   Nov 25
    11°C | 5°C
    N 7 km/h
    5 mm
    overcast and heavy rain

    overcast and heavy rain