Sumas is a small town in Whatcom County, Washington, United States. The population was 1,307 at the 2010 census. Sumas is located adjacent to the Canada–US border and borders the city of Abbotsford, British Columbia. The Sumas-Huntingdon port of entry at the north end of State Route 9 operates 24 hours a day. Sumas shares Nooksack Valley School District with the towns of Nooksack and Everson. Sumas is the northernmost settlement on Washington State Route 9 and experiences Astronomical Twilight for 22 days during the months of June and July.