Frost dates for 92021 — El Cajon, CA
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 El Cajon compares
- In a typical year, frost nights in El Cajon fall between December 21 and January 6. In 1 year in 10 the first frost comes as early as December 1, or the last frost as late as February 7.
- Nearby San Diego, CA, 22 km away, rarely gets frost, a reminder of how much elevation and distance from the coast matter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 13 |
| 50% (median) | January 6 |
| 10% (safe for tender plants) | February 7 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | December 1 |
| 50% (median) | December 21 |
| 90% (late) | January 15 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Gardening where frost is rare
El Cajon, CA only freezes on a few winter nights, so the usual "plant after the last frost" rule doesn't apply. Heat and rainfall decide the seasons instead:
- Cool-season crops (lettuce, broccoli, peas, carrots) grow best from fall through late winter.
- Warm-season crops (tomatoes, peppers, beans, squash) do best planted in late winter to spring, and again in late summer for a fall crop — midsummer heat can stop tomatoes setting fruit.
- Heat lovers (okra, sweet potatoes, melons) can be planted through spring and early summer.
About these dates
Based on 1991–2020 NOAA climate normals for the El Cajon, CA weather station, 2 km away (elevation 495 ft (151 m)).
ZIP codes in El Cajon: 92019 92020 92021 92022
Frost dates near El Cajon
- Lakeside Jan 6 · Dec 21
- Santee Jan 6 · Dec 21
- La Mesa Jan 6 · Dec 21
- Spring Valley Jan 6 · Dec 21
- Lemon Grove Jan 6 · Dec 21
- Jamul Jan 6 · Dec 21
- Alpine Feb 12 · Dec 24
- Bonita rare frost
Frequently asked questions
When is the last frost in El Cajon, CA?
The median last spring frost in El Cajon, CA is January 6. There is still about a 10% chance of frost after February 7, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in El Cajon, CA?
The median first fall frost is December 21, with about a 10% chance of frost before December 1.
How long is the growing season in El Cajon, CA?
About 349 days between the median last spring frost and first fall frost.
What planting zone is El Cajon, CA?
El Cajon, CA is in USDA hardiness zone 10a.