Scottsdale, Arizona: planting zone & frost dates
Scottsdale is in USDA plant hardiness zone 10a, where the average coldest winter night reaches 30 to 35°F (-1.1 to 1.7°C). The typical last spring frost is around Feb 13 and the first fall frost around Dec 11.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Mar 5 | Nov 28 |
| Typical planning date (30% risk) | Feb 13 | Dec 11 |
| Median (50%) | Jan 27 | Dec 21 |
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 PINNACLE PEAK, AZ (USC00026603), 3.0 mi (4.8 km) from the city center and 226 ft higher than the city center (+69 m). Record used for the 1991–2020 normals: 16 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Scottsdale
Scottsdale spans more than one half-zone. Share of the city's land area by zone (via its 10 ZIP codes): 10a (61%), 9b (39%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Scottsdale
Dates are counted from the 30%-risk frost dates above (last frost Feb 13, first frost Dec 11). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Dec 19 – Jan 2 | Feb 20 – Mar 6 | — | — |
| Pepper | Dec 5 – Dec 19 | Feb 27 – Mar 13 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Jan 2 – Jan 16 | Jan 30 – Feb 20 | Jan 16 – Feb 27 | Oct 2 – Oct 30 |
| Green Beans | — | — | Feb 20 – Mar 27 | Sep 18 – Oct 2 |
| Sweet Corn | — | — | Feb 20 – Mar 20 | — |
| Zucchini & Summer Squash | Jan 16 – Jan 23 | Feb 20 – Mar 6 | Feb 20 – Mar 13 | Sep 18 – Oct 2 |
| Cucumber | Jan 16 – Jan 23 | Feb 27 – Mar 6 | Feb 20 – Mar 13 | Sep 18 – Oct 2 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 23 – Feb 27 | Sep 18 – Oct 2 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 21 – Dec 5 | Jan 16 – Jan 30 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Jan 16 – Feb 6 | — | — |
| Basil | Jan 2 – Jan 16 | Feb 27 – Mar 13 | Feb 27 – Mar 20 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 2 – Jan 30 | Oct 16 – Nov 13 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 19 – Jan 2 | Jan 16 – Feb 6 | Jan 16 – Feb 6 | Oct 2 – Oct 30 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 19 – Jan 2 | Jan 30 – Feb 20 | — | Sep 18 – Oct 2 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 2 – Jan 23 | Oct 2 – Oct 16 |
| Eggplant | Dec 5 – Dec 19 | Feb 27 – Mar 13 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 19 – Jan 2 | Jan 16 – Jan 30 | — | Sep 18 – Oct 2 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 9 – Feb 27 | Oct 30 – Nov 27 |
| Strawberry | — | Jan 16 – Feb 6 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 23 – Mar 6 | Oct 2 – Oct 16 |
Nearby cities in Arizona
- Phoenix — zone 9b, last frost Jan 23, first frost Dec 15
- Tempe — zone 9b, last frost Feb 24, first frost Nov 29
- Mesa — zone 9b, last frost Feb 12, first frost Dec 2
- Glendale — zone 9b, last frost Feb 2, first frost Dec 8
- Gilbert — zone 9b, last frost Feb 12, first frost Dec 3
- Chandler — zone 9b, last frost Feb 24, first frost Nov 29
More: all Arizona cities · other zone 10a cities: Los Angeles, CA, Oakland, CA, Tampa, FL, Orlando, FL, Riverside, CA, Corpus Christi, TX, Port St. Lucie, FL, Santa Clarita, CA
Scottsdale gardening questions
When is the last frost in Scottsdale, AZ?
Plan around Feb 13. At NOAA's Pinnacle Peak, AZ station, 3.0 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 27, and after Mar 5 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Jan 6. Springs here are erratic: 72 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 Scottsdale, AZ?
Start seeds indoors Dec 19 – Jan 2 and set transplants outside Feb 20 – Mar 6, once nights stay above 50°F and the soil is near 60°F. With about 301 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 Scottsdale?
About 330 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 285 days, and in 1 year in 10 it runs 365 days or more. In fall there is a 10% chance of frost by Nov 28 and a 30% chance by Dec 11. That ranks 6th longest of 16 Arizona cities on this site.
When should I plant a fall garden in Scottsdale?
Count back from the first fall frost (Dec 11): transplant broccoli Sep 18 – Oct 2; sow kale Oct 2 – Oct 30; sow lettuce Oct 2 – Oct 30; sow radishes Oct 30 – Nov 27. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Jan 1. How the math works: succession and fall planting.
Did Scottsdale's hardiness zone change on the 2023 map?
Yes. Most of Scottsdale was zone 9b on the 2012 map and is zone 10a on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
Is all of Scottsdale in zone 10a?
No. Zone 10a covers about 61% of the city's land; the rest is in 9b (39%), measured across the city's 10 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.