USDA hardiness zone 9b
In zone 9b, the average annual extreme minimum temperature is 25 to 30°F (-3.9 to -1.1°C), based on 1991–2020 data from the 2023 USDA Plant Hardiness Zone Map.
What zone 9b means for your garden
A plant labeled "hardy to zone 9b" should survive a typical winter low of 25°F. Tropical and subtropical plants are an option, but many temperate fruit trees may not get enough winter chill. Zone 9a is the colder half of zone 9.
ZIP codes in zone 9b: 2,085 in contiguous U.S.. New to zones? Read how to read your hardiness zone.
Frost dates in zone 9b
Across 63 major cities in zone 9b, the 30%-risk last spring frost ranges from Jan 8 to Mar 25 (median Feb 12), and the first fall frost has a median of Dec 3. 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 9b
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 | Dec 18 – Jan 1 | Feb 19 – Mar 5 | — | — |
| Pepper | Dec 4 – Dec 18 | Feb 26 – Mar 12 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Jan 1 – Jan 15 | Jan 29 – Feb 19 | Jan 15 – Feb 26 | Sep 24 – Oct 22 |
| Green Beans | — | — | Feb 19 – Mar 26 | Sep 10 – Sep 24 |
| Sweet Corn | — | — | Feb 19 – Mar 19 | — |
| Zucchini & Summer Squash | Jan 15 – Jan 22 | Feb 19 – Mar 5 | Feb 19 – Mar 12 | Sep 10 – Sep 24 |
| Cucumber | Jan 15 – Jan 22 | Feb 26 – Mar 5 | Feb 19 – Mar 12 | Sep 10 – Sep 24 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 22 – Feb 26 | Sep 10 – Sep 24 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 20 – Dec 4 | Jan 15 – Jan 29 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Jan 15 – Feb 5 | — | — |
| Basil | Jan 1 – Jan 15 | Feb 26 – Mar 12 | Feb 26 – Mar 19 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 1 – Jan 29 | Oct 8 – Nov 5 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 18 – Jan 1 | Jan 15 – Feb 5 | Jan 15 – Feb 5 | Sep 24 – Oct 22 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 18 – Jan 1 | Jan 29 – Feb 19 | — | Sep 10 – Sep 24 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 1 – Jan 22 | Sep 24 – Oct 8 |
| Eggplant | Dec 4 – Dec 18 | Feb 26 – Mar 12 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 18 – Jan 1 | Jan 15 – Jan 29 | — | Sep 10 – Sep 24 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 8 – Feb 26 | Oct 22 – Nov 19 |
| Strawberry | — | Jan 15 – Feb 5 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 22 – Mar 5 | Sep 24 – Oct 8 |
Cities in zone 9b (63)
Major cities whose center falls in zone 9b:
- Houston, TX — last frost Feb 18, first frost Dec 8
- Phoenix, AZ — last frost Jan 23, first frost Dec 15
- Jacksonville, FL — last frost Feb 15, first frost Dec 24
- San Jose, CA — last frost Jan 10, first frost Dec 14
- Fresno, CA — last frost Jan 29, first frost Dec 6
- Sacramento, CA — last frost Jan 22, first frost Dec 7
- Mesa, AZ — last frost Feb 12, first frost Dec 2
- Bakersfield, CA — last frost Feb 12, first frost Dec 1
- New Orleans, LA — last frost Feb 1, first frost Dec 29
- Henderson, NV — last frost Feb 14, first frost Nov 28
- Stockton, CA — last frost Feb 19, first frost Nov 28
- North Las Vegas, NV — last frost Feb 11, first frost Dec 1
- Gilbert, AZ — last frost Feb 12, first frost Dec 3
- Chandler, AZ — last frost Feb 24, first frost Nov 29
- Laredo, TX — last frost Feb 5, first frost Dec 6
- Glendale, AZ — last frost Feb 2, first frost Dec 8
- Fremont, CA — last frost Jan 8, first frost Dec 19
- Modesto, CA — last frost Feb 10, first frost Nov 29
- Moreno Valley, CA — last frost Feb 10, first frost Dec 11
- Peoria, AZ — last frost Feb 16, first frost Dec 2
- Tempe, AZ — last frost Feb 24, first frost Nov 29
- Elk Grove, CA — last frost Feb 17, first frost Nov 26
- Surprise, AZ — last frost Feb 16, first frost Dec 2
- Roseville, CA — last frost Mar 5, first frost Nov 17
- Salinas, CA — last frost Feb 12, first frost Dec 2
- Sunnyvale, CA — last frost Jan 18, first frost Dec 15
- Pasadena, TX — last frost Feb 10, first frost Dec 10
- Visalia, CA — last frost Feb 2, first frost Dec 6
- Santa Clara, CA — last frost Jan 26, first frost Dec 12
- Pearland, TX — last frost Feb 15, first frost Dec 10
- Clovis, CA — last frost Jan 29, first frost Dec 6
- Concord, CA — last frost Jan 23, first frost Dec 6
- Vallejo, CA — last frost Mar 25, first frost Nov 12
- Fairfield, CA — last frost Jan 28, first frost Dec 7
- League City, TX — last frost Feb 15, first frost Dec 3
- Antioch, CA — last frost Jan 22, first frost Dec 10
- Goodyear, AZ — last frost Jan 29, first frost Dec 12
- Menifee, CA — last frost Feb 10, first frost Dec 10
- Buckeye, AZ — last frost Jan 18, first frost Dec 16
- Temecula, CA — last frost Feb 14, first frost Jan 3
- Santa Maria, CA — last frost Feb 18, first frost Dec 5
- Sugar Land, TX — last frost Feb 20, first frost Dec 3
- Palm Coast, FL — last frost Feb 2, first frost Jan 1
- Vacaville, CA — last frost Mar 3, first frost Nov 21
- Chico, CA — last frost Mar 15, first frost Nov 10
- Deltona, FL — last frost Feb 6, first frost Jan 2
- Tracy, CA — last frost Mar 9, first frost Nov 20
- Avondale, AZ — last frost Jan 18, first frost Dec 16
- Manteca, CA — last frost Feb 17, first frost Nov 24
- Redding, CA — last frost Mar 17, first frost Nov 16
- Hemet, CA — last frost Feb 14, first frost Dec 2
- Folsom, CA — last frost Jan 22, first frost Dec 7
- Citrus Heights, CA — last frost Jan 22, first frost Dec 7
- Daytona Beach, FL — last frost Feb 9, first frost Dec 29
- Baytown, TX — last frost Mar 2, first frost Nov 25
- San Ramon, CA — last frost Feb 28, first frost Nov 25
- Livermore, CA — last frost Feb 28, first frost Nov 25
- Rancho Cordova, CA — last frost Jan 22, first frost Dec 7
- Queen Creek, AZ — last frost Feb 12, first frost Dec 3
- Perris, CA — last frost Feb 10, first frost Dec 10
- Missouri City, TX — last frost Mar 1, first frost Nov 27
- Pittsburg, CA — last frost Jan 22, first frost Dec 10
- Napa, CA — last frost Feb 27, first frost Nov 28
← Zone 9a · Zone 10a → · All zones
Zone 9b questions
How cold does it get in zone 9b?
Zone 9b is defined by an average annual extreme minimum temperature of 25 to 30°F (-3.9 to -1.1°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 9b carry some risk in a severe year.
When is the last frost in zone 9b?
It depends far more on the city than on the zone. Among 63 zone 9b cities on this site, the 30%-risk last spring frost runs from Jan 8 in Fremont, CA to Mar 25 in Vallejo, CA — 76 days apart (median Feb 12).
Which states have zone 9b?
The 2023 listings put 2,085 ZIP codes in zone 9b, spread over 10 states and territories. The most are in California (819), Texas (423), Florida (333), Arizona (203), Louisiana (170).
Did zone 9b grow on the 2023 map?
Yes: 1,918 ZIP codes were in zone 9b on the 2012 map and 2,085 are on the 2023 map (+167). Of today's zone 9b ZIP codes that were also listed in 2012, 40% were in a colder zone then, 58% were already 9b, and 2% were in a warmer zone. What changed in 2023.
Which big cities are in zone 9b?
The largest cities on this site in zone 9b are Houston, TX, Phoenix, AZ, Jacksonville, FL; 63 cities in all are listed below.