Below is a list of New Castle CO zip codes. For your research we have also included New Castle Area Code, Time Zone, UTC and the local Garfield County FIPS Code. Each New Castle Colorado zip code has a center Longitude / Latitude point (the New Castle center is -107.53099822998 / 39.57149887085). For your convenience we have also indicated if that zip code in New Castle observes Daylight Savings time.