Obrien, CA frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 6 a year). Cover tender plants when frost is forecast.
How Obrien compares
- In a typical year, frost nights in Obrien fall between December 28 and February 8. In 1 year in 10 the first frost comes as early as December 1, or the last frost as late as March 28.
- Obrien shares its weather station with Redding, CA, 18 km away, so the two have the same frost dates.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 26 |
| 50% (median) | February 8 |
| 10% (safe for tender plants) | March 28 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | December 1 |
| 50% (median) | December 28 |
| 90% (late) | February 18 |
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 Obrien, CA
Obrien, CA frost dates — last frost Feb 8, first frost Dec 28, zone 9a. 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 Obrien, CA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Nov 16 – Nov 30 | Jan 11 – Jan 25 | — | — |
| Peppers | Nov 30 – Dec 14 | Feb 22 – Mar 8 | — | — |
| Eggplant | Nov 30 – Dec 14 | Feb 22 – Mar 8 | — | — |
| Tomatoes | Dec 14 – Dec 28 | Feb 15 – Mar 1 | — | — |
| Lettuce | Dec 14 – Dec 28 | Jan 18 – Feb 1 | Jan 11 – Feb 15 | Nov 2 – Nov 30 |
| Kale | Dec 14 – Dec 28 | Jan 11 – Jan 25 | Jan 11 – Jan 25 | Oct 19 – Nov 9 |
| Broccoli | Dec 14 – Dec 28 | Jan 25 – Feb 8 | — | Sep 21 – Oct 12 |
| Cabbage | Dec 14 – Dec 28 | Jan 18 – Feb 1 | — | Sep 21 – Oct 12 |
| Cauliflower | Dec 14 – Dec 28 | Jan 25 – Feb 8 | — | Sep 21 – Oct 12 |
| Okra | Dec 28 – Jan 11 | Mar 1 – Mar 15 | Mar 1 – Mar 15 | — |
| Basil | Dec 28 – Jan 11 | Feb 15 – Mar 1 | — | — |
| Peas | — | — | Dec 28 – Jan 18 | Oct 5 – Oct 26 |
| Spinach | — | — | Dec 28 – Jan 18 | Nov 2 – Nov 23 |
| Radishes | — | — | Jan 4 – Feb 15 | Nov 16 – Dec 7 |
| Cucumbers | Jan 11 – Jan 18 | Feb 22 – Mar 1 | Feb 15 – Mar 1 | Oct 12 – Oct 26 |
| Zucchini & Summer Squash | Jan 11 – Jan 18 | — | Feb 15 – Mar 1 | Oct 19 – Nov 2 |
| Winter Squash & Pumpkins | Jan 11 – Jan 18 | — | Feb 15 – Mar 1 | — |
| Melons & Watermelon | Jan 11 – Jan 18 | Feb 22 – Mar 8 | — | — |
| Carrots | — | — | Jan 18 – Feb 15 | Oct 5 – Oct 19 |
| Beets | — | — | Jan 18 – Feb 15 | Oct 19 – Nov 2 |
| Potatoes | — | — | Jan 18 – Feb 8 | — |
| Swiss Chard | — | — | Jan 25 – Feb 22 | Oct 19 – Nov 2 |
| Cilantro | — | — | Jan 25 – Feb 15 | Nov 2 – Nov 23 |
| Green Beans | — | — | Feb 15 – Mar 8 | Oct 12 – Oct 26 |
| Sweet Corn | — | — | Feb 15 – Mar 1 | — |
| Sweet Potatoes | — | Feb 22 – Mar 15 | — | — |
| Garlic | — | — | — | Dec 14 – Jan 18 |
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 Shasta Dam, CA weather station, 19 km away (elevation 1,076 ft (328 m)).
Frost dates near Obrien
- Bella Vista Feb 8 · Dec 28
- Oak Run Mar 3 · Nov 21
- Shasta Lake Feb 8 · Dec 28
- Palo Cedro Mar 3 · Nov 21
- Redding Feb 8 · Dec 28
- Millville Mar 3 · Nov 21
- Round Mountain Jun 3 · Sep 14
- Lakehead Feb 8 · Dec 28
- Whitmore Jun 9 · Sep 21
- Shasta Feb 13 · Dec 13
Frequently asked questions
When is the last frost in Obrien, CA?
The median last spring frost in Obrien, CA is February 8. There is still about a 10% chance of frost after March 28, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Obrien, CA?
The median first fall frost is December 28, with about a 10% chance of frost before December 1.
How long is the growing season in Obrien, CA?
About 323 days between the median last spring frost and first fall frost.
What planting zone is Obrien, CA?
Obrien, CA is in USDA hardiness zone 9a.