Avondale, Arizona: planting zone & frost dates
Avondale is in USDA plant hardiness zone 9b, where the average coldest winter night reaches 25 to 30°F (-3.9 to -1.1°C). The typical last spring frost is around Jan 18 and the first fall frost around Dec 16.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Feb 5 | Dec 6 |
| Typical planning date (30% risk) | Jan 18 | Dec 16 |
| Median (50%) | Jan 7 | Dec 24 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station LITCHFIELD PARK, AZ (USC00024977), 4.5 mi (7.2 km) from the city center and 66 ft higher than the city center (+20 m). Record used for the 1991–2020 normals: 22 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Avondale
All 5 ZIP codes covering Avondale are in zone 9b.
Vegetable planting calendar for Avondale
Dates are counted from the 30%-risk frost dates above (last frost Jan 18, first frost Dec 16). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Nov 23 – Dec 7 | Jan 25 – Feb 8 | — | — |
| Pepper | Nov 9 – Nov 23 | Feb 1 – Feb 15 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 7 – Dec 21 | Jan 4 – Jan 25 | Dec 21 – Feb 1 | Oct 7 – Nov 4 |
| Green Beans | — | — | Jan 25 – Mar 1 | Sep 23 – Oct 7 |
| Sweet Corn | — | — | Jan 25 – Feb 22 | — |
| Zucchini & Summer Squash | Dec 21 – Dec 28 | Jan 25 – Feb 8 | Jan 25 – Feb 15 | Sep 23 – Oct 7 |
| Cucumber | Dec 21 – Dec 28 | Feb 1 – Feb 8 | Jan 25 – Feb 15 | Sep 23 – Oct 7 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 28 – Feb 1 | Sep 23 – Oct 7 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Oct 26 – Nov 9 | Dec 21 – Jan 4 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Dec 21 – Jan 11 | — | — |
| Basil | Dec 7 – Dec 21 | Feb 1 – Feb 15 | Feb 1 – Feb 22 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 7 – Jan 4 | Oct 21 – Nov 18 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 23 – Dec 7 | Dec 21 – Jan 11 | Dec 21 – Jan 11 | Oct 7 – Nov 4 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 23 – Dec 7 | Jan 4 – Jan 25 | — | Sep 23 – Oct 7 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 7 – Dec 28 | Oct 7 – Oct 21 |
| Eggplant | Nov 9 – Nov 23 | Feb 1 – Feb 15 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 23 – Dec 7 | Dec 21 – Jan 4 | — | Sep 23 – Oct 7 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 14 – Feb 1 | Nov 4 – Dec 2 |
| Strawberry | — | Dec 21 – Jan 11 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 28 – Feb 8 | Oct 7 – Oct 21 |
Nearby cities in Arizona
- Goodyear — zone 9b, last frost Jan 29, first frost Dec 12
- Glendale — zone 9b, last frost Feb 2, first frost Dec 8
- Surprise — zone 9b, last frost Feb 16, first frost Dec 2
- Buckeye — zone 9b, last frost Jan 18, first frost Dec 16
- Phoenix — zone 9b, last frost Jan 23, first frost Dec 15
- Peoria — zone 9b, last frost Feb 16, first frost Dec 2
More: all Arizona cities · other zone 9b cities: Houston, TX, Phoenix, AZ, Jacksonville, FL, San Jose, CA, Fresno, CA, Sacramento, CA, Mesa, AZ, Bakersfield, CA
Avondale gardening questions
When is the last frost in Avondale, AZ?
Plan around Jan 18. At NOAA's Litchfield Park, AZ station, 4.5 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Jan 7, and after Feb 5 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Jan 5. Springs here are erratic: 50 days separate the 90% and 10% dates, versus a median of 36 days for cities on this site, so watch the forecast rather than the calendar.
When should I plant tomatoes in Avondale, AZ?
Start seeds indoors Nov 23 – Dec 7 and set transplants outside Jan 25 – Feb 8, once nights stay above 50°F and the soil is near 60°F. With about 332 frost-free days, frost is not the main limit — fruit set drops when nights stay above about 75°F, so early plantings tend to do best. More: tomato planting dates by zone.
How long is the growing season in Avondale?
About 351 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 320 days, and in 1 year in 10 it runs 365 days or more. In fall there is a 10% chance of frost by Dec 6 and a 30% chance by Dec 16. That ranks 3rd longest of 16 Arizona cities on this site.
When should I plant a fall garden in Avondale?
Count back from the first fall frost (Dec 16): transplant broccoli Sep 23 – Oct 7; sow kale Oct 7 – Nov 4; sow lettuce Oct 7 – Nov 4; sow radishes Nov 4 – Dec 2. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Jan 4. How the math works: succession and fall planting.
Did Avondale's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Avondale is zone 9b on both the 2012 and the 2023 USDA maps (PRISM/OSU ZIP listings). About 42% of U.S. ZIP codes kept their half-zone in 2023. Why the 2023 map is warmer.
How does Avondale compare with Glendale, AZ?
Both are in zone 9b. The typical last spring frost in Avondale (Jan 18) comes about 15 days earlier than in Glendale, AZ (Feb 2), 11 miles away, and the first fall frost is Dec 16 versus Dec 8. Avondale sits about 169 ft lower, which explains part of the gap. The two cities use different NOAA stations.