Annual mean
Annual mean of daily highs
Annual mean of daily lows
Sumas city, Washington
Official LSAD Designation: Sumas city • Census GEOID: 5368330
• Whatcom County
Climate Normals & Weather Observations
30-year climate normals (1991–2020) and weather observations for Sumas city.
Reference Weather Station: CLEARBROOK, WA US (ID: USC00451484)
• Located 3.4 miles from community center
• Elevation: 19.5 m
| Month | Average High (°F) | Average Low (°F) | Mean Temp (°F) | Precipitation (in) |
|---|---|---|---|---|
| January | 43.5° | 32.1° | 37.8° | 6.98" |
| February | 47.5° | 33.3° | 40.4° | 3.85" |
| March | 52.8° | 35.8° | 44.3° | 5.00" |
| April | 59.1° | 39.2° | 49.2° | 3.97" |
| May | 66.3° | 44.6° | 55.5° | 3.17" |
| June | 70.2° | 49.2° | 59.7° | 2.39" |
| July | 76.0° | 51.2° | 63.6° | 1.45" |
| August | 76.5° | 50.4° | 63.4° | 1.50" |
| September | 71.0° | 46.5° | 58.7° | 2.93" |
| October | 59.3° | 41.8° | 50.5° | 5.31" |
| November | 49.1° | 36.3° | 42.7° | 7.11" |
| December | 42.8° | 32.1° | 37.5° | 6.19" |
Annual Temperature History
2010–2025, completed calendar years only.
NOAA station CLEARBROOK, WA US (ID: USC00451484) • 3.4 miles from community center .
This is the same reference station used for monthly normals.
Source: NOAA NCEI Global Summary of the Year.
Annual temperature data table (°F)
| Year | Annual mean (°F) | Annual mean of daily highs (°F) | Annual mean of daily lows (°F) |
|---|---|---|---|
| 2010 | 51.3 | 59.4 | 43.2 |
| 2011 | 49.2 | 57.3 | 41.1 |
| 2012 | 50.3 | 58.7 | 41.8 |
| 2013 | 50.7 | 59.0 | 42.3 |
| 2014 | 51.9 | 60.5 | 43.4 |
| 2015 | 52.9 | 62.3 | 43.5 |
| 2016 | 52.6 | 60.9 | 44.3 |
| 2017 | 50.5 | 59.4 | 41.7 |
| 2018 | 51.3 | 60.4 | 42.2 |
| 2019 | 50.2 | 59.5 | 41.0 |
| 2020 | 50.6 | 59.3 | 41.9 |
| 2021 | 50.7 | 59.6 | 41.9 |
| 2022 | 50.3 | 59.5 | 41.1 |
| 2023 | 51.0 | 60.3 | 41.7 |
| 2024 | 51.2 | 59.7 | 42.7 |
| 2025 | Unavailable | Unavailable | Unavailable |
Source: NOAA NCEI 1991–2020 U.S. Climate Normals, National Weather Service.