USDA hardiness zone 10b
In zone 10b, the average annual extreme minimum temperature is 35 to 40°F (1.7 to 4.4°C), based on 1991–2020 data from the 2023 USDA Plant Hardiness Zone Map.
What zone 10b means for your garden
A plant labeled "hardy to zone 10b" should survive a typical winter low of 35°F. Tropical and subtropical plants are an option, but many temperate fruit trees may not get enough winter chill. Zone 10a is the colder half of zone 10.
ZIP codes in zone 10b: 751 in contiguous U.S., 1 in Hawaii. New to zones? Read how to read your hardiness zone.
Frost dates in zone 10b
Across 9 major cities in zone 10b, the 30%-risk last spring frost ranges from Jan 13 to Jan 31 (median Jan 27), and the first fall frost has a median of Dec 13. In 27 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 10b
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 2 – Dec 16 | Feb 3 – Feb 17 | — | — |
| Pepper | Nov 18 – Dec 2 | Feb 10 – Feb 24 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 16 – Dec 30 | Jan 13 – Feb 3 | Dec 30 – Feb 10 | Oct 4 – Nov 1 |
| Green Beans | — | — | Feb 3 – Mar 10 | Sep 20 – Oct 4 |
| Sweet Corn | — | — | Feb 3 – Mar 3 | — |
| Zucchini & Summer Squash | Dec 30 – Jan 6 | Feb 3 – Feb 17 | Feb 3 – Feb 24 | Sep 20 – Oct 4 |
| Cucumber | Dec 30 – Jan 6 | Feb 10 – Feb 17 | Feb 3 – Feb 24 | Sep 20 – Oct 4 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 6 – Feb 10 | Sep 20 – Oct 4 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 4 – Nov 18 | Dec 30 – Jan 13 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Dec 30 – Jan 20 | — | — |
| Basil | Dec 16 – Dec 30 | Feb 10 – Feb 24 | Feb 10 – Mar 3 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 16 – Jan 13 | Oct 18 – Nov 15 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 2 – Dec 16 | Dec 30 – Jan 20 | Dec 30 – Jan 20 | Oct 4 – Nov 1 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 2 – Dec 16 | Jan 13 – Feb 3 | — | Sep 20 – Oct 4 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 16 – Jan 6 | Oct 4 – Oct 18 |
| Eggplant | Nov 18 – Dec 2 | Feb 10 – Feb 24 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 2 – Dec 16 | Dec 30 – Jan 13 | — | Sep 20 – Oct 4 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 23 – Feb 10 | Nov 1 – Nov 29 |
| Strawberry | — | Dec 30 – Jan 20 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 6 – Feb 17 | Oct 4 – Oct 18 |
Cities in zone 10b (36)
Major cities whose center falls in zone 10b:
- San Diego, CA — frost rare
- San Francisco, CA — frost rare
- Long Beach, CA — frost rare
- Anaheim, CA — frost rare
- Irvine, CA — last frost Jan 14, first frost Dec 13
- Santa Ana, CA — frost rare
- Chula Vista, CA — last frost Jan 17, first frost Dec 22
- St. Petersburg, FL — last frost Jan 28, first frost Jan 7
- Cape Coral, FL — last frost Jan 28, first frost Jan 7
- Oxnard, CA — frost rare
- Huntington Beach, CA — frost rare
- Garden Grove, CA — frost rare
- Coral Springs, FL — frost rare
- Torrance, CA — last frost Jan 27, first frost Dec 16
- Orange, CA — frost rare
- West Palm Beach, FL — frost rare
- Davie, FL — frost rare
- Downey, CA — frost rare
- Costa Mesa, CA — frost rare
- El Monte, CA — last frost Jan 13, first frost Dec 28
- Inglewood, CA — frost rare
- Plantation, FL — frost rare
- Sunrise, FL — frost rare
- Fort Myers, FL — last frost Jan 28, first frost Jan 7
- Norwalk, CA — frost rare
- Mission Viejo, CA — frost rare
- Carson, CA — frost rare
- Compton, CA — frost rare
- South Gate, CA — frost rare
- Santa Barbara, CA — last frost Jan 27, first frost Dec 29
- Lake Forest, CA — frost rare
- Whittier, CA — frost rare
- Hawthorne, CA — frost rare
- Boynton Beach, FL — last frost Jan 31, first frost Jan 7
- Newport Beach, CA — frost rare
- Lauderhill, FL — frost rare
← Zone 10a · Zone 11a → · All zones
Zone 10b questions
How cold does it get in zone 10b?
Zone 10b is defined by an average annual extreme minimum temperature of 35 to 40°F (1.7 to 4.4°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 10b carry some risk in a severe year.
When is the last frost in zone 10b?
It depends far more on the city than on the zone. Among 9 zone 10b cities on this site, the 30%-risk last spring frost runs from Jan 13 in El Monte, CA to Jan 31 in Boynton Beach, FL — 18 days apart (median Jan 27).
Which states have zone 10b?
The 2023 listings put 752 ZIP codes in zone 10b, spread over 4 states and territories. The most are in California (525), Florida (222), Texas (1), Hawaii (1).
Did zone 10b grow on the 2023 map?
Yes: 674 ZIP codes were in zone 10b on the 2012 map and 752 are on the 2023 map (+78). Of today's zone 10b ZIP codes that were also listed in 2012, 42% were in a colder zone then, 58% were already 10b, and 0% were in a warmer zone. What changed in 2023.
Which big cities are in zone 10b?
The largest cities on this site in zone 10b are San Diego, CA, San Francisco, CA, Long Beach, CA; 36 cities in all are listed below.
How long is the growing season in zone 10b?
The median frost-free season across 9 zone 10b cities is 365 days, from 365 days in Irvine to 365 days in Boynton Beach.