Below is a list of Johnstown CO zip codes. For your research we have also included Johnstown Area Code, Time Zone, UTC and the local Weld County FIPS Code. Each Johnstown Colorado zip code has a center Longitude / Latitude point (the Johnstown center is -104.98000335693 / 40.335601806641). For your convenience we have also indicated if that zip code in Johnstown observes Daylight Savings time.