30-year climate normals
King County Climate and Weather Averages
Hottest month — August
76.7°average daily high. The coldest month is February, averaging a low of 35.3°F.
King County gets 63.28" of precipitation a year and 3.6" of snow, and 42% of it falls in Nov, Dec, Jan.
Temperature through the year
Each bar spans the average daily low to the average daily high for that month.
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| January | 46.4° | 35.8° | 8.64" | 1.5" |
| February | 49.6° | 35.3° | 5.83" | 0.2" |
| March | 53.7° | 37.2° | 6.74" | 0.3" |
| April | 58.9° | 40.1° | 5.29" | 0.0" |
| May | 64.1° | 46.1° | 4.04" | 0.0" |
| June | 69.0° | 50.6° | 3.15" | 0.0" |
| July | 75.8° | 54.0° | 1.24" | 0.0" |
| August | 76.7° | 53.7° | 1.22" | 0.0" |
| September | 70.4° | 49.1° | 3.02" | 0.0" |
| October | 59.5° | 43.5° | 6.22" | 0.0" |
| November | 51.1° | 38.3° | 9.47" | 0.1" |
| December | 45.8° | 35.7° | 8.42" | 1.5" |
Rainfall by month
Precipitation is spread fairly evenly through the year here, with 42% falling in the wettest three months (Nov, Dec, Jan).
What this climate costs you
Degree days measure how hard a building has to work to stay comfortable. They are the reason two identical houses have very different power bills, and they are the link between the weather here and what you pay every month.
These are rough planning figures from degree days and the state electricity price, not a bill estimate. House size, insulation and fuel type move them a lot. See the full cost of owning a home in King County, where electricity is one line of eight.
Common questions
What is the weather like in King County?
King County averages a high of 76.7°F in August and a low of 35.3°F in February. Annual precipitation is 63.28 inches, including 3.6 inches of snow.
When is the rainy season in King County?
The wettest stretch is Nov, Dec, Jan, which accounts for 42% of the year's precipitation. Precipitation is relatively evenly distributed across the year.
How hot does it get in King County?
The average daily high in August, the hottest month, is 76.7°F. That drives 151 cooling degree days a year, which is what your air conditioning has to work against.
Does it snow in King County?
Yes. King County averages 3.6 inches of snow a year.
Sources
- Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station SNOQUALMIE FALLS, WA US (USC00457773), 3.5 miles from the county centroid.
- Heating and cooling degree days — NOAA, same station and period.
- Electricity price — US Energy Information Administration, Electric Power Monthly Table 5.6.A, Washington residential average.
- Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.