Huntsville, Alabama: planting zone & frost dates
Huntsville is in USDA plant hardiness zone 8a, where the average coldest winter night reaches 10 to 15°F (-12.2 to -9.4°C). The typical last spring frost is around Mar 31 and the first fall frost around Nov 2.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Apr 8 | Oct 27 |
| Typical planning date (30% risk) | Mar 31 | Nov 2 |
| Median (50%) | Mar 24 | Nov 8 |
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 HUNTSVILLE INTL AP, AL (USW00003856), 7.3 mi (11.7 km) from the city center and 16 ft lower than the city center (-5 m). Record used for the 1991–2020 normals: 30 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Huntsville
Huntsville spans more than one half-zone. Share of the city's land area by zone (via its 19 ZIP codes): 8a (98%), 7b (2%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Huntsville
Dates are counted from the 30%-risk frost dates above (last frost Mar 31, first frost Nov 2). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Feb 3 – Feb 17 | Apr 7 – Apr 21 | — | — |
| Pepper | Jan 20 – Feb 3 | Apr 14 – Apr 28 | — | — |
| Lettuce | Feb 17 – Mar 3 | Mar 17 – Apr 7 | Mar 3 – Apr 14 | Aug 24 – Sep 21 |
| Green Beans | — | — | Apr 7 – May 12 | Aug 10 – Aug 24 |
| Sweet Corn | — | — | Apr 7 – May 5 | — |
| Zucchini & Summer Squash | Mar 3 – Mar 10 | Apr 7 – Apr 21 | Apr 7 – Apr 28 | Aug 10 – Aug 24 |
| Cucumber | Mar 3 – Mar 10 | Apr 14 – Apr 21 | Apr 7 – Apr 28 | Aug 10 – Aug 24 |
| Carrot | — | — | Mar 10 – Apr 14 | Aug 10 – Aug 24 |
| Onion | Jan 6 – Jan 20 | Mar 3 – Mar 17 | — | — |
| Potato | — | Mar 3 – Mar 24 | — | — |
| Basil | Feb 17 – Mar 3 | Apr 14 – Apr 28 | Apr 14 – May 5 | — |
| Spinach | — | — | Feb 17 – Mar 17 | Sep 7 – Oct 5 |
| Kale | Feb 3 – Feb 17 | Mar 3 – Mar 24 | Mar 3 – Mar 24 | Aug 24 – Sep 21 |
| Broccoli | Feb 3 – Feb 17 | Mar 17 – Apr 7 | — | Aug 10 – Aug 24 |
| Peas | — | — | Feb 17 – Mar 10 | Aug 24 – Sep 7 |
| Eggplant | Jan 20 – Feb 3 | Apr 14 – Apr 28 | — | — |
| Cabbage | Feb 3 – Feb 17 | Mar 3 – Mar 17 | — | Aug 10 – Aug 24 |
| Radish | — | — | Feb 24 – Apr 14 | Sep 21 – Oct 19 |
| Strawberry | — | Mar 3 – Mar 24 | — | — |
| Beets | — | — | Mar 10 – Apr 21 | Aug 24 – Sep 7 |
Nearby cities in Alabama
- Birmingham — zone 8a, last frost Mar 30, first frost Nov 6
- Hoover — zone 8b, last frost Mar 29, first frost Nov 2
- Tuscaloosa — zone 8b, last frost Mar 25, first frost Nov 5
- Montgomery — zone 8b, last frost Mar 13, first frost Nov 9
- Auburn — zone 8b, last frost Mar 21, first frost Nov 10
- Mobile — zone 9a, last frost Mar 3, first frost Nov 28
More: all Alabama cities · other zone 8a cities: Charlotte, NC, Memphis, TN, Atlanta, GA, Raleigh, NC, Greensboro, NC, Durham, NC, Winston-Salem, NC, Chesapeake, VA
Huntsville gardening questions
When is the last frost in Huntsville, AL?
Plan around Mar 31. At NOAA's Huntsville Int'l Airport, AL station, 7.3 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 Mar 24, and after Apr 8 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 10. The 90% and 10% dates are 35 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Huntsville, AL?
Start seeds indoors Feb 3 – Feb 17 and set transplants outside Apr 7 – Apr 21, once nights stay above 50°F and the soil is near 60°F. That leaves 216 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Huntsville?
About 229 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 208 days, and in 1 year in 10 it runs 255 days or more. In fall there is a 10% chance of frost by Oct 27 and a 30% chance by Nov 2. That is the shortest of the 7 Alabama cities on this site.
When should I plant a fall garden in Huntsville?
Count back from the first fall frost (Nov 2): transplant broccoli Aug 10 – Aug 24; sow kale Aug 24 – Sep 21; sow lettuce Aug 24 – Sep 21; sow radishes Sep 21 – Oct 19. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 20. How the math works: succession and fall planting.
Did Huntsville's hardiness zone change on the 2023 map?
Yes. Most of Huntsville was zone 7b on the 2012 map and is zone 8a 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 Huntsville in zone 8a?
No. Zone 8a covers about 98% of the city's land; the rest is in 7b (2%), measured across the city's 19 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.