Frost dates for 93403 — San Luis Obispo, 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 San Luis Obispo compares
- In a typical year, frost nights in San Luis Obispo fall between December 25 and January 16. In 1 year in 10 the first frost comes as early as November 25, or the last frost as late as February 26.
- Compared with Santa Maria, CA, 44 km away, the last frost here is 19 days earlier than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 11 |
| 50% (median) | January 16 |
| 10% (safe for tender plants) | February 26 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 25 |
| 50% (median) | December 25 |
| 90% (late) | February 12 |
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
San Luis Obispo, 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 San Luis Obispo Poly, CA weather station, 3 km away (elevation 308 ft (94 m)).
ZIP codes in San Luis Obispo: 93401 93403 93405 93406 93407 93408 93409 93410
Frost dates near San Luis Obispo
- Avila Beach Feb 1 · Jan 4
- Pismo Beach Feb 1 · Jan 4
- Los Osos Jan 19 · Jan 14
- Grover Beach Feb 1 · Jan 4
- Atascadero Jan 19 · Jan 14
- Morro Bay Jan 19 · Jan 14
- Arroyo Grande Feb 1 · Jan 4
- Oceano Feb 1 · Jan 4
Frequently asked questions
When is the last frost in San Luis Obispo, CA?
The median last spring frost in San Luis Obispo, CA is January 16. There is still about a 10% chance of frost after February 26, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in San Luis Obispo, CA?
The median first fall frost is December 25, with about a 10% chance of frost before November 25.
How long is the growing season in San Luis Obispo, CA?
About 343 days between the median last spring frost and first fall frost.
What planting zone is San Luis Obispo, CA?
San Luis Obispo, CA is in USDA hardiness zone 10a.