Below is a list of Middletown CA zip codes. For your research we have also included Middletown Area Code, Time Zone, UTC and the local Lake County FIPS Code. Each Middletown California zip code has a center Longitude / Latitude point (the Middletown center is -122.61499786377 / 38.75239944458). For your convenience we have also indicated if that zip code in Middletown observes Daylight Savings time.