USDA zone 10b in California
USDA plant hardiness zone 10b covers 34 locations across California (average annual extreme minimum 35 to 40 °F): Anaheim, CA, Avalon, CA, Carlsbad, CA, Chula Vista, CA, Daly, CA, Daly, CA, and 28 more. Average last spring frost across this group ranges January 2 (Los Angeles) to February 13 (Fort Hunter Liggett), and growing seasons run 323–364 days (Fort Hunter Liggett to Los Angeles) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every California location's own frost dates; the printable planting calendar uses Eastern Goleta Valley, this group's median-season location.
- USDA zone
- 10b35 to 40 °F
- Last frost range
- Jan 2–Feb 13avg, 32°F
- First frost range
- Dec 15–Dec 27avg, 32°F
- Growing season range
- 323–364days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Anaheim | Orange, Fullerton, Whittier, Hacienda Heights, Placentia, North Tustin, +2 more | Anaheim | frost-free | frost-free | 365 |
| Avalon | — | Avalon Catalina Ap | frost-free | frost-free | 365 |
| Carlsbad | Encinitas, Solana Beach | Carlsbad Palomar Ap | frost-free | frost-free | 365 |
| Chula Vista | Bonita, Imperial Beach | San Diego Brown Fld | frost-free | frost-free | 365 |
| Daly | Brisbane, Sausalito, Emeryville, Broadmoor | San Francisco Dwtn | frost-free | frost-free | 365 |
| Daly | Sausalito, Broadmoor | San Francisco Oceanside | frost-free | frost-free | 365 |
| Eastern Goleta Valley * | — | Santa Barbara Muni Ap | Jan 11 | Dec 16 | 342 |
| Emeryville | — | Oakland Museum | frost-free | frost-free | 365 |
| Fort Hunter Liggett | — | Big Sur Stn | Feb 13 | Dec 27 | 323 |
| Irvine | Santa Ana, Huntington Beach, Orange, Newport Beach, Garden Grove, Mission Viejo, +6 more | Santa Ana Fire Stn | frost-free | frost-free | 365 |
| Long Beach | Huntington Beach, Carson, Downey, Seal Beach, Compton, Norwalk, +7 more | Long Beach Daugherty Fld | frost-free | frost-free | 365 |
| Los Angeles | Downey, Montebello, Pico Rivera, Monterey Park, East Los Angeles, South Gate, +3 more | Los Angeles Dwtn Usc Campus | frost-free | frost-free | 365 |
| Los Angeles | — | Los Angeles Intl Ap | frost-free | frost-free | 365 |
| Los Angeles | — | Burbank Valley Pump Plt | Jan 2 | Dec 26 | 364 |
| Los Angeles | — | U C L A | frost-free | frost-free | 365 |
| Los Angeles | Torrance, Carson, Rancho Palos Verdes, Rolling Hills Estates, Rolling Hills, West Carson, +1 more | Torrance Ap | frost-free | frost-free | 365 |
| Newport Beach | Mission Viejo, Rancho Santa Margarita, Laguna Beach, Aliso Viejo | Newport Beach Harbor | frost-free | frost-free | 365 |
| Oxnard | — | Oxnard Ventura Co Ap | frost-free | frost-free | 365 |
| Pasadena | El Monte, Alhambra, Avocado Heights | Pasadena | frost-free | frost-free | 365 |
| Port Hueneme | — | Point Mugu Nf | frost-free | frost-free | 365 |
| Rancho Mission Viejo | Rancho Santa Margarita, Trabuco Canyon | Elsinore | Jan 28 | Dec 18 | 329 |
| Rosemead | South El Monte, Rose Hills | San Gabriel Fire Dept | frost-free | frost-free | 365 |
| San Clemente | Camp Pendleton Mainside | Oceanside Marina | frost-free | frost-free | 365 |
| San Clemente | Laguna Niguel, San Juan Capistrano, Dana Point | Laguna Beach | frost-free | frost-free | 365 |
| San Diego | Chula Vista, National, Bonita, Imperial Beach | Chula Vista | frost-free | frost-free | 365 |
| San Diego | Spring Valley, Crest | El Cajon | Jan 6 | Dec 21 | 350 |
| San Diego | — | San Diego Lindbergh Fld | frost-free | frost-free | 365 |
| San Diego | Coronado | North Island Nas | frost-free | frost-free | 365 |
| San Diego | Del Mar | San Diego Montgomery Fld | frost-free | frost-free | 365 |
| Santa Barbara | Toro Canyon, Mission Canyon, Summerland | Santa Barbara | frost-free | frost-free | 365 |
| Silverado | Modjeska | Irvine Rch | frost-free | frost-free | 365 |
| Temecula | — | Fallbrook 5 Ne | frost-free | frost-free | 365 |
| Thousand Oaks | Topanga, Calabasas, Agoura Hills, Oak Park, Lake Sherwood, Pepperdine University | Woodland Hills Pierce College | Jan 24 | Dec 15 | 329 |
| Thousand Oaks | — | Camarillo Ap | frost-free | frost-free | 365 |
* Eastern Goleta Valley is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Eastern Goleta Valley, representative)
Computed from Eastern Goleta Valley's average frost dates — the median-season location in this Californiazone 10b group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Jan 1 | Jan 18 – Jan 25 | Mar 19 – Apr 8 | — | matures comfortably |
| Pepper | Very tender | Jan 1 | Jan 25 – Feb 1 | Mar 26 – Apr 25 | — | matures comfortably |
| Cucumber | Tender | Jan 1 | Jan 18 – Jan 25 | Mar 9 – Mar 29 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Jan 18 – Jan 25 | Mar 4 – Mar 19 | — | matures comfortably |
| Bush bean | Tender | — | Jan 18 – Jan 25 | Mar 9 – Mar 19 | Oct 17 – Oct 27 | matures comfortably |
| Sweet corn | Tender | — | Jan 11 – Jan 25 | Mar 12 – Apr 11 | — | matures comfortably |
| Basil | Very tender | Jan 1 | Jan 18 – Jan 25 | Feb 17 – Mar 4 | — | matures comfortably |
| Lettuce | Half-hardy | Jan 1 | Jan 1 | Feb 15 – Mar 2 | Oct 3 – Oct 18 | matures comfortably |
| Pea | Hardy | — | Jan 1 | Feb 25 – Mar 12 | Sep 23 – Oct 8 | matures comfortably |
| Spinach | Hardy | — | Jan 1 | Feb 10 – Feb 20 | Oct 13 – Oct 23 | matures comfortably |
| Carrot | Half-hardy | — | Jan 1 | Mar 2 – Mar 22 | Sep 13 – Oct 3 | matures comfortably |
| Broccoli | Half-hardy | Jan 1 | Jan 1 | Feb 25 – Mar 17 | Sep 18 – Oct 8 | matures comfortably |
Which crops fit this growing season
Using Eastern Goleta Valley's own 342-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Eastern Goleta Valley)
From NOAA's 1991–2020 Climate Normals at station USW00023190. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Feb 13 | Mar 17 | Dec 1 | Dec 20 | 290 |
| 32°F (freeze) | Jan 11 | Feb 13 | Dec 16 | Jan 18 | 342 |
| 28°F | Dec 30 | Jan 18 | Dec 26 | Jan 12 | 365 |
| 24°F | — | — | — | — | 365 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 34 locations is 4,931; Eastern Goleta Valley's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 3,460 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 7,047 | cool-season crops (brassicas, greens) |
Hardiness zone 10b in California
Zone 10b means an average annual extreme minimum winter temperature of about 35 to 40 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. California spans 12 hardiness zones in this dataset — see all California locations for the full range, including zones5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 11a.
Explore zone 10b in other states at zone 10b, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 10b mean in California?
- Zone 10b means an average annual extreme minimum winter temperature of 35 to 40 °F — the standard USDA measure of which perennials survive winter. 34 locations in California fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in California's zone 10b is the growing season longest?
- Los Angeles runs the longest season on this page at about 364 days; Fort Hunter Liggett is shortest at about 323 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in California's zone 10b?
- Using Eastern Goleta Valley's frost dates (this page's median-season location): start seeds indoors about Jan 1, then transplant outside about Jan 18 – Jan 25. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in California's zone 10b have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 34 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.