Sudden Valley, Washington
| Sudden Valley, Washington | |
|---|---|
| Location of Sudden Valley, Washington | |
| Coordinates: 48°43′53″N 122°21′45″W / 48.73139°N 122.36250°W | |
| Country | United States | 
| State | Washington | 
| County | Whatcom | 
| Area | |
|  • Total | 8.1 sq mi (21.0 km2) | 
| • Land | 6.2 sq mi (16.1 km2) | 
| • Water | 1.9 sq mi (4.8 km2) | 
| Elevation | 748 ft (228 m) | 
| Population  (2020) | |
|  • Total | 6,354 | 
| • Density | 780/sq mi (300/km2) | 
| Time zone | UTC-8 (Pacific (PST)) | 
| • Summer (DST) | UTC-7 (PDT) | 
| Area code | 360 | 
| FIPS code | 53-68200 | 
| GNIS feature ID | 2410015 | 
| Website | http://suddenvalley.com/ | 
Sudden Valley is a census-designated place (CDP) just outside of Bellingham in Whatcom County, Washington. The population was 6,354 at the 2020 census, down from 6,441 at the 2010 census.
Sudden Valley is the second-largest homeowner association in western Washington, with over 7,000 residents.