In Utah, the last spring frost usually comes between April 21 and June 10, and the first fall frost between September 14 and October 25, depending on where you live. Most of Utah is in USDA hardiness zones 5b to 7b.
Find the frost dates for your ZIP code
Frost dates from NOAA 1991–2020 U.S. Climate Normals, nearest weather station. Zones derived from the 2023 USDA Plant Hardiness Zone Map data (PRISM Climate Group, Oregon State University). This is not the official USDA Plant Hardiness Zone Map.
Frost dates for Utah cities
Dates come from the NOAA weather station closest to each city. The last spring frost and first fall frost are the typical dates, with a 30% chance of frost after (or before) them. The safer planting date has only a 10% chance of a later spring frost: use it for tender plants like tomatoes, peppers and basil.
| City | Zone | Last frost | Safer date | First frost |
|---|---|---|---|---|
| Salt Lake City | 7b | April 7 | April 19 | Nov. 1 |
| Provo | 7a | April 25 | May 5 | Oct. 16 |
| Ogden | 6b | April 28 | May 6 | Oct. 17 |
| Saint George | 8b | March 25 | April 6 | Nov. 5 |
| Logan | 6a | May 6 | May 19 | Oct. 10 |
| Tooele | 7a | May 11 | May 28 | Oct. 11 |
| Cedar City | 6b | May 30 | June 8 | Sep. 25 |
| Vernal | 5b | May 12 | May 25 | Oct. 2 |
Frost dates vary a lot across Utah. Among the cities above, Saint George has the earliest last frost (around March 25) and Cedar City the latest (around May 30), about 9 weeks apart. Elevation, nearby water and local terrain all make a difference, so use the dates for the place closest to you, or look up your ZIP code.
Growing zones in Utah
Most of Utah is in USDA hardiness zones 5b to 7b. A typical frost-free growing season lasts about 163 days, longer in the warmest areas and shorter in the coldest.
Find planting dates for the main zones in Utah:
- Zone 5 (about 12% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
- Zone 6 (about 56% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
- Zone 7 (about 28% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
See all crops in our planting guides, or build a planting calendar for your ZIP code.
How to use frost dates
- Cool-season crops such as peas, lettuce, spinach and onions can go in several weeks before your last spring frost.
- Warm-season crops such as tomatoes, peppers, squash and beans wait until after it, when the soil has warmed.
- Fall crops are timed back from your first fall frost, and garlic and tulips are planted around it.
- Frost dates are averages. Check the forecast before setting out tender plants.
Frequently asked questions
When is the last frost in Utah?
It depends on where you live. Across most of Utah, the last spring frost comes between April 21 and June 10. In Salt Lake City, it is around April 7.
When is the first frost in Utah?
Across most of Utah, the first fall frost comes between September 14 and October 25. In Salt Lake City, it is around November 1.
What planting zone is Utah?
Most of Utah is in USDA hardiness zones 5b to 7b. Enter your ZIP code above to find your exact zone.
When can I plant tomatoes in Utah?
Plant tomatoes outside after your last frost, once nights stay above 50 °F. In Salt Lake City, the safer date, with only a 10% chance of a later frost, is around April 19. See when to plant tomatoes in zone 7.
Sources. Frost dates come from the nearest NOAA weather station to each city or ZIP code. Zones come from the 2023 USDA Plant Hardiness Zone Map ZIP code data. Our zone lookup is not the official USDA map.