USDA hardiness zone 9a
In zone 9a, the average annual extreme minimum temperature is 20 to 25°F (-6.7 to -3.9°C), based on 1991–2020 data from the 2023 USDA Plant Hardiness Zone Map.
What zone 9a means for your garden
A plant labeled "hardy to zone 9a" should survive a typical winter low of 20°F. Tropical and subtropical plants are an option, but many temperate fruit trees may not get enough winter chill. Zone 9b is the warmer half of zone 9.
ZIP codes in zone 9a: 2,199 in contiguous U.S.. New to zones? Read how to read your hardiness zone.
Frost dates in zone 9a
Across 34 major cities in zone 9a, the 30%-risk last spring frost ranges from Feb 4 to Apr 11 (median Mar 11), and the first fall frost has a median of Nov 19. In 1 more cities frost is rare. Frost timing depends on elevation, latitude and distance from water — a zone does not set a frost date, so check your city page for local dates.
Typical planting calendar for zone 9a
Based on the median frost dates above. For your exact dates, use your city page.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Jan 14 – Jan 28 | Mar 18 – Apr 1 | — | — |
| Pepper | Dec 31 – Jan 14 | Mar 25 – Apr 8 | — | — |
| Lettuce | Jan 28 – Feb 11 | Feb 25 – Mar 18 | Feb 11 – Mar 25 | Sep 10 – Oct 8 |
| Green Beans | — | — | Mar 18 – Apr 22 | Aug 27 – Sep 10 |
| Sweet Corn | — | — | Mar 18 – Apr 15 | — |
| Zucchini & Summer Squash | Feb 11 – Feb 18 | Mar 18 – Apr 1 | Mar 18 – Apr 8 | Aug 27 – Sep 10 |
| Cucumber | Feb 11 – Feb 18 | Mar 25 – Apr 1 | Mar 18 – Apr 8 | Aug 27 – Sep 10 |
| Carrot | — | — | Feb 18 – Mar 25 | Aug 27 – Sep 10 |
| Onion | Dec 17 – Dec 31 | Feb 11 – Feb 25 | — | — |
| Potato | — | Feb 11 – Mar 4 | — | — |
| Basil | Jan 28 – Feb 11 | Mar 25 – Apr 8 | Mar 25 – Apr 15 | — |
| Spinach | — | — | Jan 28 – Feb 25 | Sep 24 – Oct 22 |
| Kale | Jan 14 – Jan 28 | Feb 11 – Mar 4 | Feb 11 – Mar 4 | Sep 10 – Oct 8 |
| Broccoli | Jan 14 – Jan 28 | Feb 25 – Mar 18 | — | Aug 27 – Sep 10 |
| Peas | — | — | Jan 28 – Feb 18 | Sep 10 – Sep 24 |
| Eggplant | Dec 31 – Jan 14 | Mar 25 – Apr 8 | — | — |
| Cabbage | Jan 14 – Jan 28 | Feb 11 – Feb 25 | — | Aug 27 – Sep 10 |
| Radish | — | — | Feb 4 – Mar 25 | Oct 8 – Nov 5 |
| Strawberry | — | Feb 11 – Mar 4 | — | — |
| Beets | — | — | Feb 18 – Apr 1 | Sep 10 – Sep 24 |
Cities in zone 9a (35)
Major cities whose center falls in zone 9a:
- San Antonio, TX — last frost Mar 5, first frost Nov 18
- Austin, TX — last frost Mar 2, first frost Nov 26
- Seattle, WA — last frost Mar 16, first frost Nov 15
- Las Vegas, NV — last frost Feb 4, first frost Dec 4
- Portland, OR — last frost Mar 6, first frost Nov 22
- Tucson, AZ — last frost Feb 17, first frost Nov 30
- Baton Rouge, LA — last frost Mar 10, first frost Nov 15
- Tallahassee, FL — last frost Mar 19, first frost Nov 13
- Mobile, AL — last frost Mar 3, first frost Nov 28
- Santa Rosa, CA — last frost Mar 7, first frost Nov 21
- Palmdale, CA — last frost Mar 27, first frost Nov 12
- Charleston, SC — last frost Feb 17, first frost Dec 20
- Savannah, GA — last frost Mar 12, first frost Nov 21
- Gainesville, FL — last frost Mar 13, first frost Nov 24
- Round Rock, TX — last frost Mar 19, first frost Nov 13
- College Station, TX — last frost Mar 6, first frost Nov 22
- North Charleston, SC — last frost Mar 15, first frost Nov 19
- Lafayette, LA — last frost Mar 7, first frost Nov 19
- New Braunfels, TX — last frost Mar 18, first frost Nov 10
- Conroe, TX — last frost Mar 4, first frost Nov 24
- Beaumont, TX — last frost Feb 26, first frost Nov 26
- Gresham, OR — last frost Mar 27, first frost Nov 9
- Renton, WA — last frost Mar 22, first frost Nov 7
- Yuma, AZ — frost rare
- Georgetown, TX — last frost Mar 15, first frost Nov 16
- Beaverton, OR — last frost Apr 11, first frost Oct 29
- Merced, CA — last frost Mar 19, first frost Nov 16
- Mount Pleasant, SC — last frost Mar 21, first frost Nov 21
- Kirkland, WA — last frost Mar 16, first frost Nov 15
- Bryan, TX — last frost Mar 6, first frost Nov 22
- Leander, TX — last frost Mar 15, first frost Nov 16
- Lake Charles, LA — last frost Feb 26, first frost Nov 28
- Cedar Park, TX — last frost Mar 19, first frost Nov 13
- Maricopa, AZ — last frost Mar 3, first frost Nov 18
- Gulfport, MS — last frost Mar 5, first frost Nov 25
← Zone 8b · Zone 9b → · All zones
Zone 9a questions
How cold does it get in zone 9a?
Zone 9a is defined by an average annual extreme minimum temperature of 20 to 25°F (-6.7 to -3.9°C) for 1991–2020 — the average of each year's single coldest night, not the record low. Individual winters can be colder, so plants rated exactly for zone 9a carry some risk in a severe year.
When is the last frost in zone 9a?
It depends far more on the city than on the zone. Among 34 zone 9a cities on this site, the 30%-risk last spring frost runs from Feb 4 in Las Vegas, NV to Apr 11 in Beaverton, OR — 66 days apart (median Mar 11).
Which states have zone 9a?
The 2023 listings put 2,199 ZIP codes in zone 9a, spread over 13 states and territories. The most are in Texas (552), Louisiana (344), Florida (270), California (236), Georgia (211).
Did zone 9a grow on the 2023 map?
Yes: 1,722 ZIP codes were in zone 9a on the 2012 map and 2,199 are on the 2023 map (+477). Of today's zone 9a ZIP codes that were also listed in 2012, 60% were in a colder zone then, 38% were already 9a, and 2% were in a warmer zone. What changed in 2023.
Which big cities are in zone 9a?
The largest cities on this site in zone 9a are San Antonio, TX, Austin, TX, Seattle, WA; 35 cities in all are listed below.