Frost dates for 93409 — San Luis Obispo, CA
Frost is light and occasional here — typically a few cold nights around midwinter (about 8 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 11 and January 31. In 1 year in 10 the first frost comes as early as November 20, or the last frost as late as March 7.
- Compared with Santa Maria, CA, 37 km away, the last frost here is 4 days earlier than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 23 |
| 50% (median) | January 31 |
| 10% (safe for tender plants) | March 7 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 20 |
| 50% (median) | December 11 |
| 90% (late) | January 13 |
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 San Luis Obispo, CA
Frost dates for 93409 — San Luis Obispo, CA — last frost Jan 31, first frost Dec 11, 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 San Luis Obispo, CA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Nov 8 – Nov 22 | Jan 3 – Jan 17 | — | — |
| Peppers | Nov 22 – Dec 6 | Feb 14 – Feb 28 | — | — |
| Eggplant | Nov 22 – Dec 6 | Feb 14 – Feb 28 | — | — |
| Tomatoes | Dec 6 – Dec 20 | Feb 7 – Feb 21 | — | — |
| Lettuce | Dec 6 – Dec 20 | Jan 10 – Jan 24 | Jan 3 – Feb 7 | Oct 16 – Nov 13 |
| Kale | Dec 6 – Dec 20 | Jan 3 – Jan 17 | Jan 3 – Jan 17 | Oct 2 – Oct 23 |
| Broccoli | Dec 6 – Dec 20 | Jan 17 – Jan 31 | — | Sep 4 – Sep 25 |
| Cabbage | Dec 6 – Dec 20 | Jan 10 – Jan 24 | — | Sep 4 – Sep 25 |
| Cauliflower | Dec 6 – Dec 20 | Jan 17 – Jan 31 | — | Sep 4 – Sep 25 |
| Okra | Dec 20 – Jan 3 | Feb 21 – Mar 7 | Feb 21 – Mar 7 | — |
| Basil | Dec 20 – Jan 3 | Feb 7 – Feb 21 | — | — |
| Peas | — | — | Dec 20 – Jan 10 | Sep 18 – Oct 9 |
| Spinach | — | — | Dec 20 – Jan 10 | Oct 16 – Nov 6 |
| Radishes | — | — | Dec 27 – Feb 7 | Oct 30 – Nov 20 |
| Cucumbers | Jan 3 – Jan 10 | Feb 14 – Feb 21 | Feb 7 – Feb 21 | Sep 25 – Oct 9 |
| Zucchini & Summer Squash | Jan 3 – Jan 10 | — | Feb 7 – Feb 21 | Oct 2 – Oct 16 |
| Winter Squash & Pumpkins | Jan 3 – Jan 10 | — | Feb 7 – Feb 21 | — |
| Melons & Watermelon | Jan 3 – Jan 10 | Feb 14 – Feb 28 | — | — |
| Carrots | — | — | Jan 10 – Feb 7 | Sep 18 – Oct 2 |
| Beets | — | — | Jan 10 – Feb 7 | Oct 2 – Oct 16 |
| Potatoes | — | — | Jan 10 – Jan 31 | — |
| Swiss Chard | — | — | Jan 17 – Feb 14 | Oct 2 – Oct 16 |
| Cilantro | — | — | Jan 17 – Feb 7 | Oct 16 – Nov 6 |
| Green Beans | — | — | Feb 7 – Feb 28 | Sep 25 – Oct 9 |
| Sweet Corn | — | — | Feb 7 – Feb 21 | — |
| Sweet Potatoes | — | Feb 14 – Mar 7 | — | — |
| Garlic | — | — | — | Nov 27 – Jan 1 |
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 San Luis Obispo Ap, CA weather station, 2 km away (elevation 200 ft (61 m)).
ZIP codes in San Luis Obispo: 93401 93403 93405 93406 93407 93408 93409 93410
Frost dates near San Luis Obispo
- Pismo Beach Feb 1 · Jan 4
- Avila Beach Feb 1 · Jan 4
- Grover Beach Feb 1 · Jan 4
- Arroyo Grande Feb 1 · Jan 4
- Oceano Feb 1 · Jan 4
- Los Osos Jan 19 · Jan 14
- Nipomo Feb 4 · Dec 13
- Morro Bay Jan 19 · Jan 14
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 31. There is still about a 10% chance of frost after March 7, 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 11, with about a 10% chance of frost before November 20.
How long is the growing season in San Luis Obispo, CA?
About 314 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 9b.