USDA zone 7a in Arizona
USDA plant hardiness zone 7a covers 25 locations across Arizona (average annual extreme minimum 0 to 5 °F): Blue Ridge, AZ, Chinle, AZ, Concho, AZ, Dennehotso, AZ, Grand Canyon, AZ, Heber-Overgaard, AZ, and 19 more. Average last spring frost across this group ranges February 9 (Grand Canyon) to May 31 (Blue Ridge), and growing seasons run 126–295 days (Blue Ridge to Grand Canyon) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Arizona location's own frost dates; the printable planting calendar uses Lukachukai, this group's median-season location.
- USDA zone
- 7a0 to 5 °F
- Last frost range
- Feb 9–May 31avg, 32°F
- First frost range
- Oct 2–Dec 5avg, 32°F
- Growing season range
- 126–295days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Blue Ridge | — | Blue Ridge Rs | May 31 | Oct 2 | 126 |
| Chinle | Round Rock, Many Farms, Sehili, Cottonwood | Canyon De Chelly | May 6 | Oct 8 | 153 |
| Concho | — | Saint Johns | May 2 | Oct 14 | 164 |
| Dennehotso | — | Mexican Hat | Apr 11 | Oct 30 | 201 |
| Grand Canyon | — | Phantom Rch | Feb 9 | Dec 5 | 295 |
| Heber-Overgaard | — | Heber (black Mesa) Rs | May 23 | Oct 5 | 135 |
| Holbrook | Indian Wells, Joseph | Holbrook | Apr 22 | Oct 24 | 184 |
| Kaibab | — | Pipe Spring Nm | May 1 | Oct 19 | 168 |
| Kaibab Estates West | Seligman, Supai | Seligman | May 10 | Oct 15 | 154 |
| Kayenta | Shonto | Betatakin | May 7 | Oct 15 | 159 |
| Kykotsmovi | — | Tuba City | Apr 16 | Oct 28 | 193 |
| Leupp | — | Twin Arrows | Apr 14 | Oct 25 | 192 |
| Leupp | — | Wupatki Nm | Apr 7 | Nov 3 | 206 |
| Lukachukai * | Sanostee, Red Rock | Lukachukai | May 3 | Oct 17 | 163 |
| Munds Park | — | Oak Creek Canyon | Apr 14 | Nov 5 | 204 |
| Rainbow | — | Mc Nary 2n | May 20 | Oct 11 | 142 |
| Red Lake | — | Williams | May 22 | Oct 5 | 135 |
| Rock Point | Red Mesa, Beclabito | Teec Nos Pos | Apr 11 | Nov 1 | 200 |
| Sanders | — | Sanders | May 22 | Oct 8 | 138 |
| Second Mesa | First Mesa, Hotevilla-Bacavi | Keams Canyon | May 16 | Oct 10 | 147 |
| Show Low | Linden, White Mountain Lake, Cibecue | Show Low Ap | May 5 | Oct 15 | 162 |
| Snowflake | Taylor | Snowflake | May 11 | Oct 10 | 149 |
| Sun Valley | Woodruff | Petrified Forest Np | May 4 | Oct 16 | 162 |
| Sun Valley | — | Painted Desert Np | May 1 | Oct 20 | 169 |
| Winslow | — | Winslow Muni Ap | Apr 27 | Oct 18 | 174 |
* Lukachukai is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Lukachukai, representative)
Computed from Lukachukai's average frost dates — the median-season location in this Arizonazone 7a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Mar 8 – Mar 22 | May 10 – May 17 | Jul 9 – Jul 29 | — | matures comfortably |
| Pepper | Very tender | Feb 22 – Mar 8 | May 17 – May 24 | Jul 16 – Aug 15 | — | matures comfortably |
| Cucumber | Tender | Apr 5 – Apr 12 | May 10 – May 17 | Jun 29 – Jul 19 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | May 10 – May 17 | Jun 24 – Jul 9 | — | matures comfortably |
| Bush bean | Tender | — | May 10 – May 17 | Jun 29 – Jul 9 | Aug 18 – Aug 28 | matures comfortably |
| Sweet corn | Tender | — | May 3 – May 17 | Jul 2 – Aug 1 | — | matures comfortably |
| Basil | Very tender | Mar 22 – Apr 5 | May 10 – May 17 | Jun 9 – Jun 24 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 22 – Apr 5 | Apr 5 – Apr 19 | May 20 – Jun 4 | Aug 4 – Aug 19 | matures comfortably |
| Pea | Hardy | — | Mar 22 – Apr 5 | May 16 – May 31 | Jul 25 – Aug 9 | matures comfortably |
| Spinach | Hardy | — | Mar 22 – Apr 5 | May 1 – May 11 | Aug 14 – Aug 24 | matures comfortably |
| Carrot | Half-hardy | — | Apr 12 – Apr 19 | Jun 11 – Jul 1 | Jul 15 – Aug 4 | matures comfortably |
| Broccoli | Half-hardy | Mar 8 – Mar 22 | Apr 5 – Apr 19 | May 30 – Jun 19 | Jul 20 – Aug 9 | matures comfortably |
Which crops fit this growing season
Using Lukachukai's own 163-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Lukachukai)
From NOAA's 1991–2020 Climate Normals at station USC00025129. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | May 16 | Jun 6 | Oct 8 | Oct 20 | 144 |
| 32°F (freeze) | May 3 | May 22 | Oct 17 | Oct 30 | 163 |
| 28°F | Apr 23 | May 9 | Oct 27 | Nov 12 | 183 |
| 24°F | Apr 9 | Apr 28 | Nov 5 | Nov 20 | 208 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 25 locations is 3,391; Lukachukai's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 2,881 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 5,103 | cool-season crops (brassicas, greens) |
Hardiness zone 7a in Arizona
Zone 7a means an average annual extreme minimum winter temperature of about 0 to 5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Arizona spans 10 hardiness zones in this dataset — see all Arizona locations for the full range, including zones5b, 6a, 6b, 7b, 8a, 8b, 9a, 9b, 10a.
Explore zone 7a in other states at zone 7a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 7a mean in Arizona?
- Zone 7a means an average annual extreme minimum winter temperature of 0 to 5 °F — the standard USDA measure of which perennials survive winter. 25 locations in Arizona fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Arizona's zone 7a is the growing season longest?
- Grand Canyon runs the longest season on this page at about 295 days; Blue Ridge is shortest at about 126 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Arizona's zone 7a?
- Using Lukachukai's frost dates (this page's median-season location): start seeds indoors about Mar 8 – Mar 22, then transplant outside about May 10 – May 17. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Arizona's zone 7a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 25 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.