Below is a list of Westby MT zip codes. For your research we have also included Westby Area Code, Time Zone, UTC and the local Sheridan County FIPS Code. Each Westby Montana zip code has a center Longitude / Latitude point (the Westby center is -104.05599975586 / 48.868801116943). For your convenience we have also indicated if that zip code in Westby observes Daylight Savings time.