Hartley, CA has a population of 2,988 and is the 8,839th largest city in the United States. The population density is 461 per sq mi which is 98% higher than the California average and 409% higher than the national average. The median age in Hartley is 45 which is approximately 25% higher than the California average of 36. In Hartley, 63% of the population over 15 years of age are married, 81% speak English and 18% speak Spanish. 65% of Hartley residents were born in California, 25% were born out of state, 2% were born outside of the United States and 8% were foreign born.