Delta, CO has a population of 8,801 and is the 4,294th largest city in the United States. The population density is 660 per sq mi which is 1260% higher than the Colorado average and 628% higher than the national average. The median age in Delta is 41 which is approximately 14% higher than the Colorado average of 36. In Delta, 65% of the population over 15 years of age are married, 82% speak English and 16% speak Spanish. 50% of Delta residents were born in Colorado, 43% were born out of state, 1% were born outside of the United States and 6% were foreign born.