Newcastle (also New Castle) is an unincorporated community and census-designated place (CDP) in southwestern Iron County, Utah, United States. It lies along State Route 56, 30 mi west of Cedar City. Newcastle has a post office with the ZIP code of 84756. The population was 247 at the 2010 census. Newcastle was founded in 1910 by citizens of the more isolated Pinto. Newcastle is a small farming community which has a dairy, orchard, greenhouses producing house plants and tomatoes, and several fields. Crops produced include wheat, oats, alfalfa, corn and potatoes.

Demographics

The 2010 census reported 247 people and 92 housing units in the CDP. The 2010 census reported racial makeup was 88.7% White, 0.4% American Indian and Alaska Native, and 10.9% other races. Hispanic or Latino heritage comprised 19.0% of the population.

Climate

According to the Köppen Climate Classification system, Newcastle has a semi-arid climate, abbreviated "BSk" on climate maps.