Day Valley, CA has a population of 3,739 and is the 7,743rd largest city in the United States. The population density is 202 per sq mi which is 13% lower than the California average and 123% higher than the national average. The median age in Day Valley is 49 which is approximately 36% higher than the California average of 36. In Day Valley, 62% of the population over 15 years of age are married, 76% speak English and 12% speak Spanish. 63% of Day Valley residents were born in California, 23% were born out of state, 0% were born outside of the United States and 13% were foreign born.