Frost dates for 91943 — La Mesa, 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 La Mesa compares
- In a typical year, frost nights in La Mesa 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.
- La Mesa shares its weather station with El Cajon, CA, 8 km away, so the two have the same frost dates.
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
La Mesa, 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, 10 km away (elevation 495 ft (151 m)).
ZIP codes in La Mesa: 91941 91942 91943 91944
Frost dates near La Mesa
- Lemon Grove Jan 6 · Dec 21
- Spring Valley Jan 6 · Dec 21
- El Cajon Jan 6 · Dec 21
- Santee Jan 6 · Dec 21
- Bonita rare frost
- San Diego rare frost
- National City rare frost
- Lakeside Jan 6 · Dec 21
Frequently asked questions
When is the last frost in La Mesa, CA?
The median last spring frost in La Mesa, 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 La Mesa, 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 La Mesa, CA?
About 349 days between the median last spring frost and first fall frost.
What planting zone is La Mesa, CA?
La Mesa, CA is in USDA hardiness zone 10b.