Slater, IA has a population of 1,617 and is the 12,277th largest city in the United States. The population density is 1,206 per sq mi which is 2107% higher than the Iowa average and 1231% higher than the national average. The median age in Slater is 31 which is approximately 18% lower than the Iowa average of 38. In Slater, 68% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 83% of Slater residents were born in Iowa, 16% were born out of state, 1% were born outside of the United States and 0% were foreign born.