Arizona Planting Zones by City and ZIP Code
Arizona runs from zones 5b to 10a; 39% of its ZIPs are 9b, Phoenix is 10a and Tucson is 9b.
Arizona runs from zones 5b to 10a
The coldest night of the winter averages -15°F to -10°F in the coldest of Arizona’s ZIP codes and 30°F to 35°F in the warmest. Most of the state is zone 9b.
- 5bunder 1% of ZIPs (1), -15°F to -10°F
- 6a1% of ZIPs (6), -10°F to -5°F
- 6b5% of ZIPs (26), -5°F to 0°F
- 7a8% of ZIPs (44), 0°F to 5°F
- 7b3% of ZIPs (15), 5°F to 10°F
- 8a6% of ZIPs (29), 10°F to 15°F
- 8b12% of ZIPs (60), 15°F to 20°F
- 9a13% of ZIPs (67), 20°F to 25°F
- 9b39% of ZIPs (203), 25°F to 30°F
- 10a14% of ZIPs (71), 30°F to 35°F
Planting zones of Arizona cities
| City | Zone | Coldest night, on average | Since 2012 |
|---|---|---|---|
| Phoenix85004 | 10a | 30°F to 35°F | half a zone warmer than 2012 (9b) |
| Tucson85701 | 9b | 25°F to 30°F | same as 2012 |
| Flagstaff86001 | 6a | -10°F to -5°F | same as 2012 |
| Yuma85364 | 10a | 30°F to 35°F | same as 2012 |
| Prescott86301 | 7b | 5°F to 10°F | same as 2012 |
| Mesa85201 | 9b | 25°F to 30°F | same as 2012 |
Tap a ZIP for that address’s frost dates and this month’s jobs.
Find your zone anywhere in Arizona
A ZIP code or a town gives you its zone, how it moved since 2012, the frost dates at the nearest NOAA station, and the jobs for this month timed from them.
What to plant in Arizona this month
The calendar for Arizona's main zone, from vegetables to pruning and winter protection, each job tied to the extension page it comes from. Pick a month, or read the whole year below it.
Timed from the median frost dates of the 20 NOAA stations in Arizona’s zone 9b: last spring frost Feb 3, first fall frost Dec 13. Your own ZIP’s frost dates move every window, so the ZIP tool times them for you. The vegetables follow University of Arizona Cooperative Extension’s Vegetable Planting Calendar for Maricopa County for Arizona's low desert instead.
Pick a month above to see every job in it.
The year at a glance
- Plant vegetables: Low desert (Maricopa County)Jul to May
- Plant trees and shrubsNov 1 to Feb 17
- Plant garlicNov 29 to Jan 3
- Plant pre-chilled tulip bulbsNov 20 to Dec 31
- Divide fall-blooming perennialsJan 13 to Feb 24
- Divide spring and summer-blooming perennialsNov 1 to Dec 13
- Prune trees and summer-flowering shrubs while dormantDec 23 to Feb 3
- Prune spring-flowering shrubs after they bloomJan 20 to Mar 17
- Prune out cold damageFeb 3 to Mar 17
- Cover tender plants on a freezing nightDec 6 to Feb 3
- Cut back perennials after a hard freezeDec 20 to Jan 17
What changed in Arizona since 2012
Every ZIP on both mapsCompared ZIP by ZIP from the 2023 and 2012 USDA tables; 521 Arizona ZIP codes appear in both.
Why Arizona’s zones moved
Of the cities above, Phoenix went from 9b to 10a.
The USDA explains the national picture: “When compared to the 2012 map, the 2023 version reveals that about half of the country shifted to the next warmer half zone, and the other half of the country remained in the same half zone.” The new map uses 1991 to 2020 and more than 13,000 weather stations, so it draws Arizona’s hills, valleys and cities more finely than the 2012 map did.
A warmer zone changes which perennials and shrubs come through the winter, not when the garden gets planted; that still follows the frost dates.

Frost dates and seed starting in Arizona
Arizona planting zone questions
Planting zones by state
Sources. USDA Plant Hardiness Zone Map, ZIP code tables (2023 and 2012), PRISM Climate Group, Oregon State University; USDA Plant Hardiness Zone Map; USDA Unveils Updated Plant Hardiness Zone Map (USDA Agricultural Research Service, November 15, 2023); NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal, by station (v1.0.1); NC State Extension Gardener Plant Toolbox. Zones are read from the PRISM ZIP code tables, read Oct 9, 2026; a ZIP code’s zone is the zone at its center. The calendar’s extension sources are listed on the planting zones page and under each job.