What Planting Zones Are in Arizona?
Arizona spans USDA hardiness zones 5b to 10a, where the average coldest winter night ranges from −15 °F to 35 °F (−26.1 °C to 1.7 °C). Zone 9b covers the most ZIP codes, 39%, and zones 8b to 10a together cover 77% of the state.
- Zone 5b<1% · 1 ZIP
- Zone 6a1% · 6 ZIPs
- Zone 6b5% · 26 ZIPs
- Zone 7a8% · 44 ZIPs
- Zone 7b3% · 15 ZIPs
- Zone 8a6% · 29 ZIPs
- Zone 8b11% · 60 ZIPs
- Zone 9a13% · 67 ZIPs
- Zone 9b39% · 203 ZIPs
- Zone 10a14% · 71 ZIPs
Bars show each zone's share of the 522 Arizona ZIP codes in the official 2023 USDA ZIP code table; select a zone for its temperatures and hardy plants.
What Hardiness Zone Are Arizona Cities In?
Phoenix is in zone 9b, Tucson is in zone 9b, Mesa is in zone 9b and Gilbert is in zone 9b. The table lists the zone, winter low and average frost dates for 22 Arizona cities, using the ZIP code nearest each city center.
| City | ZIP | Zone | Winter low | Last frost | First frost |
|---|---|---|---|---|---|
| Phoenix | 85021 | 9b | 25 °F to 30 °F | Jan 8 | Dec 25 |
| Tucson | 85708 | 9b | 25 °F to 30 °F | Feb 5 | Dec 9 |
| Mesa | 85206 | 9b | 25 °F to 30 °F | Feb 1 | Dec 10 |
| Gilbert | 85295 | 9b | 25 °F to 30 °F | Feb 1 | Dec 11 |
| Chandler | 85286 | 9b | 25 °F to 30 °F | Feb 1 | Dec 11 |
| Glendale | 85301 | 9b | 25 °F to 30 °F | Jan 20 | Dec 15 |
| Scottsdale | 85255 | 10a | 30 °F to 35 °F | Jan 27 | Dec 21 |
| Peoria | 85383 | 9b | 25 °F to 30 °F | Feb 5 | Dec 11 |
| Tempe | 85282 | 10a | 30 °F to 35 °F | Feb 13 | Dec 5 |
| Surprise | 85387 | 9b | 25 °F to 30 °F | Feb 5 | Dec 11 |
| Goodyear | 85338 | 9b | 25 °F to 30 °F | Jan 7 | Dec 24 |
| Buckeye | 85343 | 9b | 25 °F to 30 °F | Jan 7 | Dec 24 |
| Yuma | 85349 | 10a | 30 °F to 35 °F | Jan 8 | Dec 28 |
| Flagstaff | 86005 | 6a | −10 °F to −5 °F | Jun 4 | Sep 28 |
| Maricopa | 85138 | 9a | 20 °F to 25 °F | Feb 23 | Nov 24 |
| Casa Grande | 85122 | 9a | 20 °F to 25 °F | Feb 5 | Dec 6 |
| Marana | 85658 | 9b | 25 °F to 30 °F | Apr 2 | Nov 11 |
| Lake Havasu City | 86403 | 10a | 30 °F to 35 °F | Jan 5 | Dec 29 |
| Sierra Vista | 85613 | 8b | 15 °F to 20 °F | Mar 16 | Nov 21 |
| Douglas | 85626 | 8a | 10 °F to 15 °F | Mar 18 | Nov 13 |
| Show Low | 85901 | 7a | 0 °F to 5 °F | May 5 | Oct 15 |
| Pinetop-Lakeside | 85929 | 6b | −5 °F to 0 °F | May 22 | Oct 6 |
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 Arizona 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 Arizona Are in Each Zone?
Zone 6a, the coldest Arizona zone with towns, covers 1% of ZIP codes around Flagstaff and Eagar. Zone 10a, the warmest, covers 14% around Scottsdale, Tempe and Yuma. The table lists the largest places in every zone.
| Zone | Avg. coldest night | Share of ZIPs | Largest places in this zone |
|---|---|---|---|
| Zone 5b | −15 °F to −10 °F | <1% (1) | Rural ZIP codes only |
| Zone 6a | −10 °F to −5 °F | 1% (6) | Flagstaff, Eagar |
| Zone 6b | −5 °F to 0 °F | 5% (26) | Pinetop-Lakeside, Williams, St. Johns, Springerville |
| Zone 7a | 0 °F to 5 °F | 8% (44) | Show Low, Winslow, Snowflake, Holbrook |
| Zone 7b | 5 °F to 10 °F | 3% (15) | Prescott Valley, Prescott, Page, Colorado City |
| Zone 8a | 10 °F to 15 °F | 6% (29) | Douglas, Chino Valley, Dewey-Humboldt |
| Zone 8b | 15 °F to 20 °F | 11% (60) | Sierra Vista, Nogales, Payson, Cottonwood |
| Zone 9a | 20 °F to 25 °F | 13% (67) | Maricopa, Casa Grande, Oro Valley, Sahuarita |
| Zone 9b | 25 °F to 30 °F | 39% (203) | Phoenix, Tucson, Mesa, Gilbert |
| Zone 10a | 30 °F to 35 °F | 14% (71) | Scottsdale, Tempe, Yuma, Lake Havasu City |
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 Arizona Gardeners?
A Arizona gardener in zone 10a sees winter lows about 45 °F milder than one in zone 5b, 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 Arizona, a plant labelled “zones 8–10” survives winter in at least 77% 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 Arizona towns in the same zone can have last frosts weeks apart.
What Plants Grow Well Across Arizona?
90 plants in PlantoScan's catalogue are hardy in every zone from 8b to 10a, the zones that cover 77% of Arizona ZIP codes. Popular examples include dahlia, arugula and alfalfa.
- DahliaDahlia pinnataPlantoScan
Dahlia
Dahlia pinnata
Zone 8a – 11b
Arugula
Eruca sativa
Zone 5a – 10b
AI generated
Alfalfa
Medicago sativa
Zone 3a – 10a
AI generated
Calla Lily
Zantedeschia aethiopica
Zone 8a – 10b
AI generated
Snapdragon
Antirrhinum majus
Zone 7a – 10b
AI generated
Gardenia
Gardenia jasminoides
Zone 8a – 11b
AI generated
Magnolia Tree
Magnolia grandiflora
Zone 7a – 10a
Joseph McPhailCC BY 4.0iNaturalistresized
Grape Vine
Vitis vinifera
Zone 5b – 10a
AI generated
Fig Tree
Ficus carica
Zone 7a – 11b
Image: PlantoScan
Hardiness ranges come from PlantoScan's plant database; gardeners in Arizona's colder or warmer edge zones should check each plant's full range.
When Is the Last Frost in Arizona?
Across most Arizona ZIP codes, the average last spring frost falls between January 7 and May 11, from January 5 in Lake Havasu City to June 4 in Flagstaff. Tender vegetables such as tomatoes go out 1 to 2 weeks after the local date.
The last and first frost dates for Arizona 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 Arizona?
- Arizona spans USDA hardiness zones 5b to 10a on the 2023 USDA Plant Hardiness Zone Map. Zone 9b is the most common, covering 39% of the state's 522 ZIP codes, and zones 8b to 10a together cover 77%.
- What hardiness zone is Phoenix, Arizona?
- Phoenix is in USDA hardiness zone 9b (ZIP 85021), where the average coldest winter night reaches 25 °F to 30 °F. Its average last spring frost is January 8 and its first fall frost December 25.
- What hardiness zone is Tucson, Arizona?
- Tucson is in USDA hardiness zone 9b (ZIP 85708), where the average coldest winter night reaches 25 °F to 30 °F. Its average last spring frost is February 5 and its first fall frost December 9.
- What hardiness zone is Mesa, Arizona?
- Mesa is in USDA hardiness zone 9b (ZIP 85206), where the average coldest winter night reaches 25 °F to 30 °F. Its average last spring frost is February 1 and its first fall frost December 10.
- What is the coldest hardiness zone in Arizona?
- Zone 5b (−15 °F to −10 °F) is the coldest zone in Arizona, found in 1 ZIP code. The warmest is zone 10a (30 °F to 35 °F), around Scottsdale and Tempe.
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.