Seattle Temperatures: Averages by Month
The numbers here tell you how hot and cold the weather usually is in Seattle, Washington during each month of the year.
The average high and low temperatures are listed below monthly and annually for Seattle, in both degrees Fahrenheit and Celsius.
Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.
To find out how often it rises over 60, 70 or 80 °F each month in Seattle, scroll down farther. There are also monthly and yearly counts of days with cold weather.
The first set of high and low temperatures are averages for 2010 to 2019 at Seattle—Tacoma International Airport. Everything else here is based on 1991 to 2020 weather, also measured at Sea–Tac.
| High °F | Low °F | High °C | Low °C | |
|---|---|---|---|---|
| 48 | 38 | January | 9 | 3 |
| 48 | 38 | February | 9 | 3 |
| 54 | 40 | March | 12 | 5 |
| 59 | 44 | April | 15 | 6 |
| 66 | 49 | May | 19 | 9 |
| 71 | 53 | June | 22 | 12 |
| 78 | 57 | July | 25 | 14 |
| 79 | 58 | August | 26 | 14 |
| 71 | 54 | September | 22 | 12 |
| 60 | 47 | October | 16 | 9 |
| 52 | 41 | November | 11 | 5 |
| 46 | 37 | December | 8 | 3 |
| 61 | 46 | Year | 16 | 8 |
| High °F | Low °F | High °C | Low °C | |
|---|---|---|---|---|
| 48 | 38 | January | 9 | 3 |
| 50 | 38 | February | 10 | 3 |
| 54 | 40 | March | 12 | 4 |
| 59 | 43 | April | 15 | 6 |
| 66 | 49 | May | 19 | 9 |
| 71 | 53 | June | 22 | 12 |
| 77 | 57 | July | 25 | 14 |
| 78 | 57 | August | 25 | 14 |
| 72 | 54 | September | 22 | 12 |
| 61 | 47 | October | 16 | 8 |
| 52 | 41 | November | 11 | 5 |
| 47 | 37 | December | 8 | 3 |
| 61 | 46 | Year | 16 | 8 |
Days of Hot Weather in Seattle
Seattle averages only four days a year of temperatures in the 90s Fahrenheit and normally doesn't get any hotter than 100 °F (38 °C).
Nights are equally moderate with minimum temperatures dropping below 70 °F. Just eight times a year, on average does the daily low remain in the 60s.
| 60 °F 16 °C |
70 °F 21 °C |
80 °F 27 °C | |
|---|---|---|---|
| January | 0 | 0 | 0 |
| February | 1 | 0 | 0 |
| March | 5 | 0 | 0 |
| April | 11 | 2 | 0 |
| May | 23 | 8 | 2 |
| June | 29 | 14 | 4 |
| July | 31 | 25 | 10 |
| August | 31 | 27 | 10 |
| September | 29 | 16 | 4 |
| October | 14 | 2 | 0 |
| November | 2 | 0 | 0 |
| December | 0 | 0 | 0 |
| Year | 177 | 94 | 31 |
How Often Seattle Has Cold Temperatures
Despite its northern US location, Seattle enjoys mild temperatures. The Pacific Ocean moderates the climate of this coastal city.
Seattle averages just one really frigid day annually, most often in December. On the coldest day of the year the thermometer drops to 20 degrees F or less and the day's highest temperature doesn't break above the freezing point.
| 32 °F 0 °C |
40 °F 4 °C | |
|---|---|---|
| January | 7 | 20 |
| February | 6 | 20 |
| March | 2 | 19 |
| April | 0 | 9 |
| May | 0 | 1 |
| June | 0 | 0 |
| July | 0 | 0 |
| August | 0 | 0 |
| September | 0 | 0 |
| October | 0 | 3 |
| November | 3 | 14 |
| December | 7 | 23 |
| Year | 25 | 110 |
References
Jay Lawrimore, Ron Ray, Scott Applequist, Bryant Korzeniewski, Matthew Menne. 2016. Global Summary of the Month and Year, Version 1.0. NOAA National Centers for Environmental Information.
NOAA National Centers for Environmental Information (NCEI). Climate Normals.