What Planting Zones Are in Utah?
Utah spans USDA hardiness zones 4a to 8b, where the average coldest winter night ranges from −30 °F to 20 °F (−34.4 °C to −6.7 °C). Zone 6a covers the most ZIP codes, 32%, and zones 6a to 7b together cover 84% of the state.
- Zone 4a<1% · 1 ZIP
- Zone 5a<1% · 3 ZIPs
- Zone 5b10% · 33 ZIPs
- Zone 6a32% · 108 ZIPs
- Zone 6b17% · 57 ZIPs
- Zone 7a18% · 60 ZIPs
- Zone 7b18% · 59 ZIPs
- Zone 8a2% · 7 ZIPs
- Zone 8b3% · 9 ZIPs
Bars show each zone's share of the 337 Utah ZIP codes in the official 2023 USDA ZIP code table; select a zone for its temperatures and hardy plants.
What Hardiness Zone Are Utah Cities In?
Salt Lake City is in zone 7b, West Valley City is in zone 7b, West Jordan is in zone 7b and Provo is in zone 7a. The table lists the zone, winter low and average frost dates for 18 Utah cities, using the ZIP code nearest each city center.
| City | ZIP | Zone | Winter low | Last frost | First frost |
|---|---|---|---|---|---|
| Salt Lake City | 84180 | 7b | 5 °F to 10 °F | Mar 31 | Nov 8 |
| West Valley City | 84120 | 7b | 5 °F to 10 °F | Apr 8 | Oct 31 |
| West Jordan | 84081 | 7b | 5 °F to 10 °F | Apr 18 | Oct 22 |
| Provo | 84606 | 7a | 0 °F to 5 °F | Apr 18 | Oct 21 |
| St. George | 84790 | 8b | 15 °F to 20 °F | Mar 14 | Nov 10 |
| Orem | 84057 | 7a | 0 °F to 5 °F | Apr 19 | Oct 19 |
| Lehi | 84043 | 7a | 0 °F to 5 °F | Apr 30 | Oct 9 |
| Sandy | 84094 | 7b | 5 °F to 10 °F | Apr 29 | Oct 22 |
| Ogden | 84408 | 6b | −5 °F to 0 °F | Apr 21 | Oct 23 |
| South Jordan | 84009 | 7a | 0 °F to 5 °F | Apr 18 | Oct 22 |
| Logan | 84341 | 6a | −10 °F to −5 °F | Apr 30 | Oct 16 |
| Tooele | 84074 | 7a | 0 °F to 5 °F | May 2 | Oct 16 |
| Cedar City | 84721 | 6b | −5 °F to 0 °F | May 21 | Sep 29 |
| Brigham City | 84302 | 6b | −5 °F to 0 °F | May 5 | Oct 5 |
| Heber | 84049 | 6a | −10 °F to −5 °F | May 31 | Sep 11 |
| Santaquin | 84655 | 6b | −5 °F to 0 °F | May 4 | Oct 11 |
| Tremonton | 84312 | 6b | −5 °F to 0 °F | Apr 24 | Oct 17 |
| Vernal | 84078 | 5b | −15 °F to −10 °F | May 6 | Oct 7 |
Zone: 2023 USDA ZIP code table for the ZIP code nearest each city's Census center point. Frost dates: 50% (median) dates from the nearest NOAA station, 1991–2020 normals. Cities: the largest Utah places by 2024 Census population estimates, spread across the state, plus the largest place in each common zone. Large cities can span two half zones.
Which Parts of Utah Are in Each Zone?
Zone 5b, the coldest Utah zone with towns, covers 10% of ZIP codes around Vernal, Roosevelt and Mount Pleasant. Zone 8b, the warmest, covers 3% around St. George, Washington and Hurricane. The table lists the largest places in every zone.
| Zone | Avg. coldest night | Share of ZIPs | Largest places in this zone |
|---|---|---|---|
| Zone 4a | −30 °F to −25 °F | <1% (1) | Rural ZIP codes only |
| Zone 5a | −20 °F to −15 °F | <1% (3) | Rural ZIP codes only |
| Zone 5b | −15 °F to −10 °F | 10% (33) | Vernal, Roosevelt, Mount Pleasant, Naples |
| Zone 6a | −10 °F to −5 °F | 32% (108) | Logan, Heber, Smithfield, North Logan |
| Zone 6b | −5 °F to 0 °F | 17% (57) | Ogden, Eagle Mountain, Bountiful, Cedar City |
| Zone 7a | 0 °F to 5 °F | 18% (60) | Provo, Orem, Lehi, South Jordan |
| Zone 7b | 5 °F to 10 °F | 18% (59) | Salt Lake City, West Valley City, West Jordan, Sandy |
| Zone 8a | 10 °F to 15 °F | 2% (7) | La Verkin |
| Zone 8b | 15 °F to 20 °F | 3% (9) | St. George, Washington, Hurricane, Ivins |
Places: incorporated places with 1,000+ residents, assigned the zone of the ZIP code nearest their Census center point.
What Do the Hardiness Zones Mean for Utah Gardeners?
A Utah gardener in zone 8b sees winter lows about 45 °F milder than one in zone 4a, so a shrub or perennial that thrives in one part of the state can die in another. Choose plants rated to your own ZIP code's zone or colder.
Hardiness zones follow latitude, elevation and large bodies of water rather than state lines. Higher ground and inland valleys that trap cold air usually sit in colder half zones, while cities, coasts and large lakes moderate winter lows. Within Utah, a plant labelled “zones 6–7” survives winter in at least 84% of ZIP codes, but plants at the edge of their range benefit from mulch and a sheltered spot. Enter a ZIP code in the USDA hardiness zone finder by ZIP code to check your exact half zone before buying perennials.
A zone describes winter cold only. Summer heat, humidity, rainfall and soil decide whether a cold-hardy plant thrives, and planting dates for vegetables follow frost dates, not zones: two Utah towns in the same zone can have last frosts weeks apart.
What Plants Grow Well Across Utah?
219 plants in PlantoScan's catalogue are hardy in every zone from 6a to 7b, the zones that cover 84% of Utah ZIP codes. Popular examples include hydrangea, peony and daisy.
Hydrangea
Hydrangea macrophylla
Zone 5 – 9
AI generated
Peony
Paeonia lactiflora
Zone 3 – 8
AI generated
- DaisyBellis perennisPlantoScan
Daisy
Bellis perennis
Zone 4a – 8b
Chrysanthemum
Chrysanthemum morifolium
Zone 5a – 9b
PlantoscanAI generated
Poppy
Papaver somniferum
Zone 3a – 9b
AI generated
Carnation
Dianthus caryophyllus
Zone 5a – 9b
AI generated
Daffodil
Narcissus poeticus
Zone 3 – 8
AI generated
Azalea
Azalea indica
Zone 6a – 9b
AI generated
Arugula
Eruca sativa
Zone 5a – 10b
AI generated
Hardiness ranges come from PlantoScan's plant database; gardeners in Utah's colder or warmer edge zones should check each plant's full range.
When Is the Last Frost in Utah?
Across most Utah ZIP codes, the average last spring frost falls between April 10 and June 3, from March 14 in St. George to May 31 in Heber. Tender vegetables such as tomatoes go out 1 to 2 weeks after the local date.
The last and first frost dates for Utah cities include the safer 90% planting date, the fall frost date, growing season length and a tomato planting table for each city.
Frequently Asked Questions
- What planting zone is Utah?
- Utah spans USDA hardiness zones 4a to 8b on the 2023 USDA Plant Hardiness Zone Map. Zone 6a is the most common, covering 32% of the state's 337 ZIP codes, and zones 6a to 7b together cover 84%.
- What hardiness zone is Salt Lake City, Utah?
- Salt Lake City is in USDA hardiness zone 7b (ZIP 84180), where the average coldest winter night reaches 5 °F to 10 °F. Its average last spring frost is March 31 and its first fall frost November 8.
- What hardiness zone is West Valley City, Utah?
- West Valley City is in USDA hardiness zone 7b (ZIP 84120), where the average coldest winter night reaches 5 °F to 10 °F. Its average last spring frost is April 8 and its first fall frost October 31.
- What hardiness zone is West Jordan, Utah?
- West Jordan is in USDA hardiness zone 7b (ZIP 84081), where the average coldest winter night reaches 5 °F to 10 °F. Its average last spring frost is April 18 and its first fall frost October 22.
- What is the coldest hardiness zone in Utah?
- Zone 4a (−30 °F to −25 °F) is the coldest zone in Utah, found in 1 ZIP code. The warmest is zone 8b (15 °F to 20 °F), around St. George and Washington.
Zones: 2023 USDA Plant Hardiness Zone Map ZIP code table, USDA Agricultural Research Service and the PRISM Climate Group, Oregon State University, used without changes. Frost dates: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals. City locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. PlantoScan is not affiliated with or endorsed by these agencies.