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Climate in Seattle, Washington: Monthly Weather Averages
Seattle sits at 370 feet above sea level, and its climate, as recorded at the Seattle Tacoma International Airport, WA station, runs to a yearly mean of 53.7°F. The warmest month is August, averaging 67.4°F with typical highs of 77.6°F; the coldest is December, averaging 42.0°F with lows around 37.1°F. Across a normal year the city receives 39.3 in of precipitation and 6.3 in of snow. The full month-by-month picture below comes from the official 1991–2020 U.S. Climate Normals — the 30-year averages the National Weather Service itself uses — so it describes the Seattle climate you should actually plan around, whether you are timing a visit, weighing a move, or just settling an argument about which month is best.
Seattle climate month by month
The table below is the complete 1991–2020 normals profile for Seattle: average high, average low and mean temperature, rainfall, and snowfall for every month. Read down the Mean column to feel the year's rhythm — Seattle's temperature range runs from 42.0°F in December to 67.4°F in August.
| Month | Avg High (°F) | Avg Low (°F) | Mean (°F) | Rain (in) | Snow (in) |
|---|---|---|---|---|---|
| January | 48.0 | 37.7 | 42.8 | 5.78 | 1.8 |
| February | 50.3 | 37.7 | 44.0 | 3.76 | 2.2 |
| March | 54.2 | 39.9 | 47.1 | 4.17 | 0.4 |
| April | 59.3 | 43.3 | 51.3 | 3.18 | 0.0 |
| May | 66.3 | 48.7 | 57.5 | 1.88 | 0.0 |
| June | 71.1 | 53.0 | 62.0 | 1.45 | 0.0 |
| July | 77.4 | 56.8 | 67.1 | 0.60 | 0.0 |
| August | 77.6 | 57.2 | 67.4 | 0.97 | 0.0 |
| September | 71.6 | 53.6 | 62.6 | 1.61 | 0.0 |
| October | 60.5 | 47.0 | 53.8 | 3.91 | 0.0 |
| November | 52.1 | 40.9 | 46.5 | 6.31 | 0.2 |
| December | 47.0 | 37.1 | 42.0 | 5.72 | 1.7 |
| Year | 61.3 | 46.1 | 53.7 | 39.34 | 6.3 |
How to read the colors:below freezingcoldcoolmildwarmhot. Bands are colored by each cell's own temperature, so a whole year reads at a glance.
Seattle through the seasons
Winter in Seattle averages highs of 47.0–50.3°F and lows of 37.1–37.7°F, a seasonal mean of 42.9°F. The three months together bring 15.3 in of precipitation — about 39% of the city's yearly total — with January the wettest of the three at 5.78 in. Snowfall averages 5.7 in over the season, most of it in February (2.2 in). It is a genuinely cold season — heavy coats, freezing nights, and the year's most changeable weather — without being locked below freezing around the clock.
Spring in Seattle averages highs of 54.2–66.3°F and lows of 39.9–48.7°F, a seasonal mean of 52.0°F. The three months together bring 9.2 in of precipitation — about 23% of the city's yearly total — with March the wettest of the three at 4.17 in. Snowfall averages 0.4 in over the season, most of it in March (0.4 in). The season is a transition: the average temperature climbs 10.4°F from March to May, and by late spring Seattle is firmly into mild territory.
Summer in Seattle averages highs of 71.1–77.6°F and lows of 53.0–57.2°F, a seasonal mean of 65.5°F. The three months together bring 3.0 in of precipitation — about 8% of the city's yearly total — with June the wettest of the three at 1.45 in. Summer is the mildest in the country by big-city standards — heat waves happen, but the average afternoon stays in the 70s, and many homes historically get by without air conditioning.
Fall in Seattle averages highs of 52.1–71.6°F and lows of 40.9–53.6°F, a seasonal mean of 54.3°F. The three months together bring 11.8 in of precipitation — about 30% of the city's yearly total — with November the wettest of the three at 6.31 in. Snowfall averages 0.2 in over the season, most of it in November (0.2 in). Temperatures ease off through the season — the monthly mean drops 16.1°F from September to November — and fall is when Seattle's weather turns cooler and wetter, while nights stay mostly frost-free into December.
Best and worst months to visit Seattle
Ranking every month by its normals — mild mean temperatures score best, heavy rain and snow count against — the most comfortable months to visit Seattle are:
JulyAugustSeptember
July leads the list: average highs of 77.4°F, lows of 56.8°F, and 0.60 in of rain, with snow a non-factor at 0.0 in. The other picks, August and September, offer the same balance in Seattle's mild stretch of the year. At the other end, December is usually the month to avoid — the least comfortable mix of temperature and rainfall, with a mean temperature of 42.0°F and 5.72 in of precipitation plus 1.7 in of snow.
How Seattle compares
Across the 114 cities in our dataset, the typical city averages 57.8°F for the year and 35.7 in of precipitation. Seattle runs 4.1°F cooler than that typical city and wetter by 3.7 in a year, ranking #70 of 114 for annual warmth and #55 of 114 for precipitation (wettest first). Its year-round temperature swing — warmest month minus coldest — is 25.4°F, which puts it in the mild, ocean- or latitude-softened camp.
Within Washington, Seattle is the warmest of the cities we track. See the Washington climate overview for the full state comparison, including Seattle (warmest, 53.7°F yearly mean) and Spokane (coolest, 48.6°F).
Planning notes for Seattle
For anyone relocating: average lows never drop below freezing in any month, so hard freezes are events, not seasons; even the warmest month's average high stays below 80°F, so summer heat is rarely a planning factor; 5 months of the year average between 55°F and 80°F, the band most people find comfortable without heating or cooling. Those four facts, all straight from the normals table above, shape everything from a Seattle wardrobe to its utility bills.
Seattle climate FAQ
What is the warmest month in Seattle?
August is the warmest month in Seattle, with a mean temperature of 67.4°F, average highs of 77.6°F and average lows of 57.2°F (1991–2020 normals).
What is the coldest month in Seattle?
December is the coldest month, averaging 42.0°F, with highs of 47.0°F and lows of 37.1°F.
How much rain does Seattle get in a year?
Seattle averages 39.34 in of precipitation a year. The wettest month is November (6.31 in) and the driest is July (0.60 in).
When is the best time of year to visit Seattle?
By the normals, the most comfortable months are July, August, September — mild average temperatures with moderate rainfall. December is typically the least comfortable month.
How much snow does Seattle get?
Seattle averages 6.3 in of snow a year, with February the snowiest month at 2.2 in on average.
Source: 1991–2020 U.S. Climate Normals, NOAA National Centers for Environmental Information (NCEI) — ncei.noaa.gov. Station: Seattle Tacoma International Airport, WA (USW00024233), elevation 370 ft. Figures checked October 2026.