Big Lake, WA has a population of 1,904 and is the 11,316th largest city in the United States. The population density is 505 per sq mi which is 331% higher than the Washington average and 457% higher than the national average. The median age in Big Lake is 49 which is approximately 30% higher than the Washington average of 38. In Big Lake, 74% of the population over 15 years of age are married, 92% speak English and 5% speak Spanish. 52% of Big Lake residents were born in Washington, 41% were born out of state, 3% were born outside of the United States and 4% were foreign born.