Hayward, California: planting zone & frost dates
Hayward 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 12 and the first fall frost around Dec 17.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Jan 27 | Dec 6 |
| Typical planning date (30% risk) | Jan 12 | Dec 17 |
| Median (50%) | Jan 2 | Dec 25 |
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 HAYWARD AIR TERMINAL, CA (USW00093228), 2.0 mi (3.2 km) from the city center and 20 ft higher than the city center (+6 m). Record used for the 1991–2020 normals: 21 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Hayward
Hayward spans more than one half-zone. Share of the city's land area by zone (via its 8 ZIP codes): 10a (56%), 9b (44%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Hayward
Dates are counted from the 30%-risk frost dates above (last frost Jan 12, first frost Dec 17). 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 17 – Dec 1 | Jan 19 – Feb 2 | — | — |
| Pepper | Nov 3 – Nov 17 | Jan 26 – Feb 9 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 1 – Dec 15 | Dec 29 – Jan 19 | Dec 15 – Jan 26 | Oct 8 – Nov 5 |
| Green Beans | — | — | Jan 19 – Feb 23 | Sep 24 – Oct 8 |
| Sweet Corn | — | — | Jan 19 – Feb 16 | — |
| Zucchini & Summer Squash | Dec 15 – Dec 22 | Jan 19 – Feb 2 | Jan 19 – Feb 9 | Sep 24 – Oct 8 |
| Cucumber | Dec 15 – Dec 22 | Jan 26 – Feb 2 | Jan 19 – Feb 9 | Sep 24 – Oct 8 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 22 – Jan 26 | Sep 24 – Oct 8 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Oct 20 – Nov 3 | Dec 15 – Dec 29 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Dec 15 – Jan 5 | — | — |
| Basil | Dec 1 – Dec 15 | Jan 26 – Feb 9 | Jan 26 – Feb 16 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 1 – Dec 29 | Oct 22 – Nov 19 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 17 – Dec 1 | Dec 15 – Jan 5 | Dec 15 – Jan 5 | Oct 8 – Nov 5 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 17 – Dec 1 | Dec 29 – Jan 19 | — | Sep 24 – Oct 8 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 1 – Dec 22 | Oct 8 – Oct 22 |
| Eggplant | Nov 3 – Nov 17 | Jan 26 – Feb 9 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 17 – Dec 1 | Dec 15 – Dec 29 | — | Sep 24 – Oct 8 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 8 – Jan 26 | Nov 5 – Dec 3 |
| Strawberry | — | Dec 15 – Jan 5 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 22 – Feb 2 | Oct 8 – Oct 22 |
Nearby cities in California
- San Leandro — zone 10a, last frost Jan 22, first frost Dec 10
- Redwood City — zone 10a, last frost Jan 31, first frost Dec 4
- Oakland — zone 10a, frost rare
- Alameda — zone 10a, last frost Jan 22, first frost Dec 10
- Fremont — zone 9b, last frost Jan 8, first frost Dec 19
- San Mateo — zone 10a, last frost Jan 3, first frost Dec 21
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
Hayward gardening questions
When is the last frost in Hayward, CA?
Plan around Jan 12. At NOAA's Hayward Air Terminal, CA station, 2.0 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 2, and after Jan 27 the risk drops to about 1 in 10. The 90% and 10% dates are 45 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Hayward, CA?
Start seeds indoors Nov 17 – Dec 1 and set transplants outside Jan 19 – Feb 2, once nights stay above 50°F and the soil is near 60°F. With about 339 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 Hayward?
About 365 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 338 days, and in 1 year in 10 it runs 365 days or more. In fall there is a 10% chance of frost by Dec 6 and a 30% chance by Dec 17. That ranks 9th longest of 84 California cities on this site.
When should I plant a fall garden in Hayward?
Count back from the first fall frost (Dec 17): transplant broccoli Sep 24 – Oct 8; sow kale Oct 8 – Nov 5; sow lettuce Oct 8 – Nov 5; sow radishes Nov 5 – Dec 3. How the math works: succession and fall planting.
Did Hayward's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Hayward 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 Hayward in zone 10a?
No. Zone 10a covers about 56% of the city's land; the rest is in 9b (44%), measured across the city's 8 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.