03/24/2026
Did you know Utah’s last spring frost can vary by nearly 3 months, even within about 80 miles? In St. George, the average last frost is around March 25, while in Panguitch it doesn’t happen until about June 18!
Frost occurs when temperatures near the ground drop to 32°F or lower, causing water inside plant cells to freeze. As ice crystals form, they can rupture cell walls, damaging, or even killing tender plants. Clear skies, calm winds, dry air, and high elevation make frost more likely because heat escapes quickly from the soil overnight.
That’s why final spring frost dates matter so much for gardening. Planting too early can expose young plants to a late cold snap, setting back growth or wiping out your hard work. Waiting until after your area’s average last frost helps ensure your plants have the warm, stable conditions they need to thrive. Even warm days can have chilly nights!
**All dates are based on previous climate data from each county's most populous city using a 30% probability threshold. Keep an eye on the forecast because there is still a chance of frost after the listed date.
You can find frost dates for your city here:
Use our 2026 Frost Dates Calculator to find the average date of the last spring frost and first fall frost in your area—based on data from the nearest official weather station and your ZIP or Postal Code. These dates estimate your growing season length and help you plan planting, harvesting, and g...