Northwood, IA has a population of 1,931 and is the 11,219th largest city in the United States. The population density is 513 per sq mi which is 839% higher than the Iowa average and 466% higher than the national average. The median age in Northwood is 43 which is approximately 13% higher than the Iowa average of 38. In Northwood, 64% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 63% of Northwood residents were born in Iowa, 35% were born out of state, 0% were born outside of the United States and 1% were foreign born.