Surfside, FL has a population of 5,810 and is the 5,868th largest city in the United States. The population density is 10,425 per sq mi which is 3451% higher than the Florida average and 11406% higher than the national average. The median age in Surfside is 42 which is approximately equal to the Florida average of 42. In Surfside, 70% of the population over 15 years of age are married, 36% speak English and 38% speak Spanish. 27% of Surfside residents were born in Florida, 26% were born out of state, 4% were born outside of the United States and 44% were foreign born.