Pasadena, California: planting zone & frost dates
Pasadena is in USDA plant hardiness zone 10a, where the average coldest winter night reaches 30 to 35°F (-1.1 to 1.7°C). The typical last spring frost is around Jan 14 and the first fall frost around Jan 1.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Feb 17 | Dec 20 |
| Typical planning date (30% risk) | Jan 14 | Jan 1 |
| Median (50%) | Jan 8 | Jan 7 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station PASADENA, CA (USC00046719), 0.9 mi (1.5 km) from the city center and 59 ft lower than the city center (-18 m). Record used for the 1991–2020 normals: 25 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Pasadena
Pasadena spans more than one half-zone. Share of the city's land area by zone (via its 9 ZIP codes): 10a (77%), 10b (23%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Pasadena
Dates are counted from the 30%-risk frost dates above (last frost Jan 14, first frost Jan 1). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Nov 19 – Dec 3 | Jan 21 – Feb 4 | — | — |
| Pepper | Nov 5 – Nov 19 | Jan 28 – Feb 11 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 3 – Dec 17 | Dec 31 – Jan 21 | Dec 17 – Jan 28 | Oct 23 – Nov 20 |
| Green Beans | — | — | Jan 21 – Feb 25 | Oct 9 – Oct 23 |
| Sweet Corn | — | — | Jan 21 – Feb 18 | — |
| Zucchini & Summer Squash | Dec 17 – Dec 24 | Jan 21 – Feb 4 | Jan 21 – Feb 11 | Oct 9 – Oct 23 |
| Cucumber | Dec 17 – Dec 24 | Jan 28 – Feb 4 | Jan 21 – Feb 11 | Oct 9 – Oct 23 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 24 – Jan 28 | Oct 9 – Oct 23 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Oct 22 – Nov 5 | Dec 17 – Dec 31 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Dec 17 – Jan 7 | — | — |
| Basil | Dec 3 – Dec 17 | Jan 28 – Feb 11 | Jan 28 – Feb 18 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 3 – Dec 31 | Nov 6 – Dec 4 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 19 – Dec 3 | Dec 17 – Jan 7 | Dec 17 – Jan 7 | Oct 23 – Nov 20 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 19 – Dec 3 | Dec 31 – Jan 21 | — | Oct 9 – Oct 23 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 3 – Dec 24 | Oct 23 – Nov 6 |
| Eggplant | Nov 5 – Nov 19 | Jan 28 – Feb 11 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 19 – Dec 3 | Dec 17 – Dec 31 | — | Oct 9 – Oct 23 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 10 – Jan 28 | Nov 20 – Dec 18 |
| Strawberry | — | Dec 17 – Jan 7 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 24 – Feb 4 | Oct 23 – Nov 6 |
Nearby cities in California
- Alhambra — zone 10a, last frost Jan 13, first frost Dec 28
- Glendale — zone 10a, last frost Jan 14, first frost Jan 1
- El Monte — zone 10b, last frost Jan 13, first frost Dec 28
- Burbank — zone 10a, last frost Jan 10, first frost Dec 16
- Downey — zone 10b, frost rare
- South Gate — zone 10b, frost rare
More: all California cities · other zone 10a cities: Los Angeles, CA, Oakland, CA, Tampa, FL, Orlando, FL, Riverside, CA, Corpus Christi, TX, Port St. Lucie, FL, Scottsdale, AZ
Pasadena gardening questions
When is the last frost in Pasadena, CA?
Plan around Jan 14. At NOAA's Pasadena, CA station, 0.9 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Jan 8, and after Feb 17 the risk drops to about 1 in 10. Springs here are erratic: 59 days separate the 90% and 10% dates, versus a median of 36 days for cities on this site, so watch the forecast rather than the calendar.
When should I plant tomatoes in Pasadena, CA?
Start seeds indoors Nov 19 – Dec 3 and set transplants outside Jan 21 – Feb 4, once nights stay above 50°F and the soil is near 60°F. With about 352 frost-free days, frost is not the main limit — fruit set drops when nights stay above about 75°F, so early plantings tend to do best. More: tomato planting dates by zone.
How long is the growing season in Pasadena?
About 365 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 363 days, and in 1 year in 10 it runs 365 days or more. In fall there is a 10% chance of frost by Dec 20 and a 30% chance by Jan 1. That ranks 12th longest of 84 California cities on this site.
When should I plant a fall garden in Pasadena?
Count back from the first fall frost (Jan 1): transplant broccoli Oct 9 – Oct 23; sow kale Oct 23 – Nov 20; sow lettuce Oct 23 – Nov 20; sow radishes Nov 20 – Dec 18. How the math works: succession and fall planting.
Did Pasadena's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Pasadena is zone 10a on both the 2012 and the 2023 USDA maps (PRISM/OSU ZIP listings). About 42% of U.S. ZIP codes kept their half-zone in 2023. Why the 2023 map is warmer.
Is all of Pasadena in zone 10a?
No. Zone 10a covers about 77% of the city's land; the rest is in 10b (23%), measured across the city's 9 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.