Alpine, CA frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 3 a year). Cover tender plants when frost is forecast.
How Alpine compares
- In a typical year, frost nights in Alpine fall between December 24 and February 12. In 1 year in 10 the first frost comes as early as December 2, or the last frost as late as March 20.
- Compared with El Cajon, CA, 17 km away, the last frost here is 37 days later than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 29 |
| 50% (median) | February 12 |
| 10% (safe for tender plants) | March 20 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | December 2 |
| 50% (median) | December 24 |
| 90% (late) | February 3 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Alpine, CA
Alpine, CA frost dates — last frost Feb 12, first frost Dec 24, zone 9b. whenisthelastfrost.com
In mild climates, summer heat limits many crops as much as frost does. Use this calendar for spring planting and lean on fall and winter for cool-season crops.
When to plant vegetables in Alpine, CA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Nov 20 – Dec 4 | Jan 15 – Jan 29 | — | — |
| Peppers | Dec 4 – Dec 18 | Feb 26 – Mar 12 | — | — |
| Eggplant | Dec 4 – Dec 18 | Feb 26 – Mar 12 | — | — |
| Tomatoes | Dec 18 – Jan 1 | Feb 19 – Mar 5 | — | — |
| Lettuce | Dec 18 – Jan 1 | Jan 22 – Feb 5 | Jan 15 – Feb 19 | Oct 29 – Nov 26 |
| Kale | Dec 18 – Jan 1 | Jan 15 – Jan 29 | Jan 15 – Jan 29 | Oct 15 – Nov 5 |
| Broccoli | Dec 18 – Jan 1 | Jan 29 – Feb 12 | — | Sep 17 – Oct 8 |
| Cabbage | Dec 18 – Jan 1 | Jan 22 – Feb 5 | — | Sep 17 – Oct 8 |
| Cauliflower | Dec 18 – Jan 1 | Jan 29 – Feb 12 | — | Sep 17 – Oct 8 |
| Okra | Jan 1 – Jan 15 | Mar 5 – Mar 19 | Mar 5 – Mar 19 | — |
| Basil | Jan 1 – Jan 15 | Feb 19 – Mar 5 | — | — |
| Peas | — | — | Jan 1 – Jan 22 | Oct 1 – Oct 22 |
| Spinach | — | — | Jan 1 – Jan 22 | Oct 29 – Nov 19 |
| Radishes | — | — | Jan 8 – Feb 19 | Nov 12 – Dec 3 |
| Cucumbers | Jan 15 – Jan 22 | Feb 26 – Mar 5 | Feb 19 – Mar 5 | Oct 8 – Oct 22 |
| Zucchini & Summer Squash | Jan 15 – Jan 22 | — | Feb 19 – Mar 5 | Oct 15 – Oct 29 |
| Winter Squash & Pumpkins | Jan 15 – Jan 22 | — | Feb 19 – Mar 5 | — |
| Melons & Watermelon | Jan 15 – Jan 22 | Feb 26 – Mar 12 | — | — |
| Carrots | — | — | Jan 22 – Feb 19 | Oct 1 – Oct 15 |
| Beets | — | — | Jan 22 – Feb 19 | Oct 15 – Oct 29 |
| Potatoes | — | — | Jan 22 – Feb 12 | — |
| Swiss Chard | — | — | Jan 29 – Feb 26 | Oct 15 – Oct 29 |
| Cilantro | — | — | Jan 29 – Feb 19 | Oct 29 – Nov 19 |
| Green Beans | — | — | Feb 19 – Mar 12 | Oct 8 – Oct 22 |
| Sweet Corn | — | — | Feb 19 – Mar 5 | — |
| Sweet Potatoes | — | Feb 26 – Mar 19 | — | — |
| Garlic | — | — | — | Dec 10 – Jan 14 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Alpine, CA weather station, 2 km away (elevation 1,696 ft (517 m)).
ZIP codes in Alpine: 91901 91903
Frost dates near Alpine
- Jamul Jan 6 · Dec 21
- Lakeside Jan 6 · Dec 21
- Descanso Apr 19 · Oct 27
- El Cajon Jan 6 · Dec 21
- Guatay Apr 22 · Nov 8
- Santee Jan 6 · Dec 21
- Pine Valley Apr 22 · Nov 8
- Ramona Mar 4 · Dec 4
- Spring Valley Jan 6 · Dec 21
- Dulzura Jan 6 · Dec 31
Frequently asked questions
When is the last frost in Alpine, CA?
The median last spring frost in Alpine, CA is February 12. There is still about a 10% chance of frost after March 20, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Alpine, CA?
The median first fall frost is December 24, with about a 10% chance of frost before December 2.
How long is the growing season in Alpine, CA?
About 315 days between the median last spring frost and first fall frost.
What planting zone is Alpine, CA?
Alpine, CA is in USDA hardiness zone 9b.