USDA zone 7a in California
USDA plant hardiness zone 7a covers 18 locations across California (average annual extreme minimum 0 to 5 °F): Big Bear, CA, Big Pine, CA, Canby, CA, Chalfant, CA, Doyle, CA, Hat Creek, CA, and 12 more. Average last spring frost across this group ranges March 31 (Big Pine) to June 11 (Johnsville), and growing seasons run 91–224 days (Johnsville to Big Pine) — 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 Lookout, this group's median-season location.
- USDA zone
- 7a0 to 5 °F
- Last frost range
- Mar 31–Jun 11avg, 32°F
- First frost range
- Sep 10–Nov 9avg, 32°F
- Growing season range
- 91–224days
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) |
|---|---|---|---|---|---|
| Big Bear | Big Bear Lake | Big Bear Lake | May 27 | Oct 4 | 131 |
| Big Pine | — | Independence | Mar 31 | Nov 9 | 224 |
| Canby | — | Alturas Muni Ap | Jun 3 | Sep 12 | 97 |
| Chalfant | — | Bishop Ap | Apr 29 | Oct 15 | 166 |
| Doyle | Herlong | Doyle 4 Sse | May 21 | Oct 1 | 130 |
| Hat Creek | McArthur, Nubieber | Hat Creek | May 29 | Sep 19 | 113 |
| Janesville | Susanville, Litchfield | Susanville 2sw | May 16 | Oct 8 | 143 |
| Johnsville | Milford, Whitehawk, Sierra | Portola | Jun 11 | Sep 10 | 91 |
| Kirkwood | Meyers, Stateline | Dagget Pass | Jun 7 | Sep 28 | 113 |
| Lookout * | Bieber, Adin | Adin Rs | May 28 | Sep 29 | 125 |
| Meyers | — | Tahoma | Jun 4 | Oct 3 | 120 |
| Mineral | — | Mineral | Jun 10 | Sep 13 | 96 |
| Old Station | — | Manzanita Lake | Jun 9 | Sep 21 | 102 |
| Soda Springs | — | Lake Spaulding | May 22 | Oct 16 | 147 |
| Sunnyside-Tahoe | Tahoe Vista, Dollar Point, Carnelian Bay, Crystal Bay | Tahoe City | Jun 9 | Sep 25 | 108 |
| Topaz | — | Topaz Lake | May 12 | Oct 6 | 145 |
| Warner Valley | Chester | Chester | May 28 | Sep 28 | 124 |
| Yosemite Valley | — | Yosemite Park Hq | Apr 21 | Oct 27 | 186 |
* Lookout 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 (Lookout, representative)
Computed from Lookout's average frost dates — the median-season location in this Californiazone 7a 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 | Apr 2 – Apr 16 | Jun 4 – Jun 11 | Aug 3 – Aug 23 | — | matures comfortably |
| Pepper | Very tender | Mar 19 – Apr 2 | Jun 11 – Jun 18 | Aug 10 – Sep 9 | — | matures comfortably |
| Cucumber | Tender | Apr 30 – May 7 | Jun 4 – Jun 11 | Jul 24 – Aug 13 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Jun 4 – Jun 11 | Jul 19 – Aug 3 | — | matures comfortably |
| Bush bean | Tender | — | Jun 4 – Jun 11 | Jul 24 – Aug 3 | Jul 31 – Aug 10 | matures comfortably |
| Sweet corn | Tender | — | May 28 – Jun 11 | Jul 27 – Aug 26 | — | matures comfortably |
| Basil | Very tender | Apr 16 – Apr 30 | Jun 4 – Jun 11 | Jul 4 – Jul 19 | — | matures comfortably |
| Lettuce | Half-hardy | Apr 16 – Apr 30 | Apr 30 – May 14 | Jun 14 – Jun 29 | Jul 17 – Aug 1 | matures comfortably |
| Pea | Hardy | — | Apr 16 – Apr 30 | Jun 10 – Jun 25 | Jul 7 – Jul 22 | matures comfortably |
| Spinach | Hardy | — | Apr 16 – Apr 30 | May 26 – Jun 5 | Jul 27 – Aug 6 | matures comfortably |
| Carrot | Half-hardy | — | May 7 – May 14 | Jul 6 – Jul 26 | Jun 27 – Jul 17 | matures comfortably |
| Broccoli | Half-hardy | Apr 2 – Apr 16 | Apr 30 – May 14 | Jun 24 – Jul 14 | Jul 2 – Jul 22 | matures comfortably |
Which crops fit this growing season
Using Lookout's own 125-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 (Lookout)
From NOAA's 1991–2020 Climate Normals at station USC00040029. 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 | Jun 13 | Jun 29 | Sep 15 | Oct 1 | 91 |
| 32°F (freeze) | May 28 | Jun 16 | Sep 29 | Oct 15 | 125 |
| 28°F | May 2 | May 29 | Oct 13 | Nov 2 | 162 |
| 24°F | Apr 13 | May 2 | Oct 30 | Nov 16 | 200 |
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 18 locations is 1,838; Lookout's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 2,289 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 4,520 | cool-season crops (brassicas, greens) |
Hardiness zone 7a in California
Zone 7a means an average annual extreme minimum winter temperature of about 0 to 5 °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, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11a.
Explore zone 7a in other states at zone 7a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 7a mean in California?
- Zone 7a means an average annual extreme minimum winter temperature of 0 to 5 °F — the standard USDA measure of which perennials survive winter. 18 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 7a is the growing season longest?
- Big Pine runs the longest season on this page at about 224 days; Johnsville is shortest at about 91 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 7a?
- Using Lookout's frost dates (this page's median-season location): start seeds indoors about Apr 2 – Apr 16, then transplant outside about Jun 4 – Jun 11. 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 7a 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 18 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.