See the average first and last frost dates for locations across the U.S. and Canada with our frost dates calculator. Oct 25, 2024 · Scroll down further to find two tables, each giving the estimated dates for 90%, 50%, and 10% chance of frost before the first frost date or after the last frost date of the year. Our frost date calculator will tell you precisely when your garden is at risk for frost. Enter your zipcode and we'll give you all the info we have. Enter your zip code (or City, State) below and we'll tell you what we know. Simply enter your zip code, city, or location to receive customized first and last frost information—the essential ….