Frost Dates for Oroville, CA 95966
Last spring frost April 20 · First fall frost November 11 · 205 frost-free days · USDA Zone 9b
ZIP 95966 has about 28,500 people, the largest of 2 ZIP codes in Oroville.
Long season: 205 frost-free days. Spring frost risk spans April 29–May 11 (12 days). Fall frost risk spans October 20–November 12 (23 days).
Frost probability for 95966
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 11 | April 20 | April 29 |
| Fall (first frost) | October 20 | November 11 | November 12 |
Dates come from NOAA 1971–2000 freeze probabilities at DOBBINS 1 S (23.7 km away); the 50% date is the median year.
Frost dates by ZIP code in Oroville, CA
| ZIP | Last spring frost (50%) | First fall frost (50%) | Zone |
|---|---|---|---|
| 95966 | April 20 | November 11 | 9b |
| 95965 | March 6 | December 2 | 9b |
Which crops fit a 205-day season in Oroville
In Oroville (205 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Mar 16 | May 4–May 11 | 163 | fits: 80 days to maturity, 163 available after May 4. | Jul 12 |
| Pepper | Mar 9 | May 4–May 11 | 163 | fits: 75 days to maturity, 163 available after May 4. | Jul 17 |
| Lettuce | Feb 23 | Mar 23–Mar 30 | 240 | two-plantings: Plant Mar 23 and again by Sep 20; both mature before Nov 18. | Sep 20 |
| Carrots | — | Mar 30–Apr 6 | 247 | fits: 70 days to maturity, 247 available after Mar 30. | Sep 9 |
| Cucumber | Mar 30 | May 4–May 11 | 177 | two-plantings: Plant May 4 and again by Aug 15; both mature before Oct 28. | Aug 15 |
| Beans | — | Apr 27–May 11 | 191 | two-plantings: Plant Apr 27 and again by Aug 22; both mature before Nov 4. | Aug 22 |
| Peas | — | Feb 23–May 4 | 268 | fits: 65 days to maturity, 268 available after Feb 23. | Aug 31 |
| Zucchini | Apr 6 | May 4–May 11 | 177 | two-plantings: Plant May 4 and again by Aug 20; both mature before Oct 28. | Aug 20 |
| Onion | Jan 26 | Mar 23–Apr 6 | 240 | fits: 100 days to maturity, 240 available after Mar 23. | — |
| Spinach | — | Feb 23–Apr 13 | 282 | two-plantings: Plant Feb 23 and again by Oct 9; both mature before Dec 2. | Oct 9 |
| Kale | Feb 9 | Mar 23–Apr 6 | 254 | two-plantings: Plant Mar 23 and again by Sep 24; both mature before Dec 2. | Sep 24 |
| Broccoli | Feb 23 | Mar 23–Apr 6 | 240 | fits: 80 days to maturity, 240 available after Mar 23. | Aug 16 |
| Cabbage | Feb 23 | Mar 23–Apr 6 | 254 | fits: 70 days to maturity, 254 available after Mar 23. | Sep 9 |
| Radish | — | Feb 23–May 18 | 268 | two-plantings: Plant Feb 23 and again by Oct 10; both mature before Nov 18. | Oct 10 |
| Beets | — | Feb 23–May 18 | 268 | two-plantings: Plant Feb 23 and again by Sep 10; both mature before Nov 18. | Sep 10 |
| Potatoes | — | Apr 6–Apr 13 | 226 | fits: 90 days to maturity, 226 available after Apr 6. | — |
| Garlic | — | Nov 11 | 310 | overwinter: Plant Nov 11 to Dec 2; harvest the following summer. | Dec 2 |
| Strawberry | — | Mar 16–May 11 | 261 | perennial: A perennial: plant Mar 16; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 23 | Apr 27–May 4 | 177 | fits: 75 days to maturity, 177 available after Apr 27. | Jul 24 |
| Pumpkin | Apr 6 | May 4–May 4 | 170 | fits: 100 days to maturity, 170 available after May 4. | Jun 29 |
| Cauliflower | Mar 9 | Apr 13–Apr 27 | 219 | fits: 75 days to maturity, 219 available after Apr 13. | Aug 21 |
| Swiss Chard | Feb 23 | Apr 6–Apr 6 | 226 | two-plantings: Plant Apr 6 and again by Sep 10; both mature before Nov 18. | Sep 10 |
| Arugula | — | Feb 23–May 18 | 282 | two-plantings: Plant Feb 23 and again by Oct 9; both mature before Dec 2. | Oct 9 |
| Brussel Sprouts | Feb 23 | Mar 23–Apr 6 | 254 | fits: 100 days to maturity, 254 available after Mar 23. | Aug 10 |
| Butternut Squash | Apr 6 | May 4–May 11 | 170 | fits: 100 days to maturity, 170 available after May 4. | Jun 29 |
| Eggplant | Mar 2 | May 4–May 11 | 163 | fits: 70 days to maturity, 163 available after May 4. | Jul 22 |
| Okra | Mar 23 | Apr 27–May 4 | 184 | two-plantings: Plant Apr 27 and again by Aug 20; both mature before Oct 28. | Aug 20 |
| Basil | Mar 16 | May 11–May 11 | 170 | two-plantings: Plant May 11 and again by Aug 15; both mature before Oct 28. | Aug 15 |
| Cilantro | — | Mar 23–Apr 13 | 240 | two-plantings: Plant Mar 23 and again by Sep 15; both mature before Nov 18. | Sep 15 |
| Parsley | Feb 9 | Apr 27–May 4 | 205 | fits: 70 days to maturity, 205 available after Apr 27. | Aug 26 |
| Celery | Feb 9 | Apr 27–May 11 | 205 | fits: 120 days to maturity, 205 available after Apr 27. | Jul 7 |
| Scallions | Feb 9 | Mar 23–Apr 6 | 254 | two-plantings: Plant Mar 23 and again by Sep 19; both mature before Dec 2. | Sep 19 |
| Turnip | — | Mar 23–Apr 6 | 254 | two-plantings: Plant Mar 23 and again by Sep 29; both mature before Dec 2. | Sep 29 |
| Kohlrabi | — | Mar 9–Mar 23 | 268 | two-plantings: Plant Mar 9 and again by Sep 24; both mature before Dec 2. | Sep 24 |
| Bok Choy | Mar 23 | Apr 13–Apr 20 | 219 | two-plantings: Plant Apr 13 and again by Sep 20; both mature before Nov 18. | Sep 20 |
| Collards | Feb 9 | Mar 23–Apr 6 | 254 | two-plantings: Plant Mar 23 and again by Sep 19; both mature before Dec 2. | Sep 19 |
| Cantaloupe | Apr 6 | May 4–May 11 | 163 | fits: 85 days to maturity, 163 available after May 4. | Jul 7 |
| Chives | Jan 26 | Apr 27–May 4 | 219 | fits: 90 days to maturity, 219 available after Apr 27. | — |
| Dill | — | Feb 23–May 18 | 268 | two-plantings: Plant Feb 23 and again by Sep 10; both mature before Nov 18. | Sep 10 |
| Oregano | Feb 9 | Apr 27–May 4 | 219 | fits: 80 days to maturity, 219 available after Apr 27. | — |
| Rosemary | Jan 26 | Apr 27–May 4 | 205 | fits: 80 days to maturity, 205 available after Apr 27. | — |
| Sage | Feb 23 | Apr 27–May 4 | 219 | fits: 75 days to maturity, 219 available after Apr 27. | — |
| Thyme | Feb 9 | Apr 27–May 4 | 219 | fits: 90 days to maturity, 219 available after Apr 27. | — |
| Calendula | Mar 9 | Apr 6–Apr 20 | 226 | two-plantings: Plant Apr 6 and again by Sep 15; both mature before Nov 18. | Sep 15 |
| Cosmos | Mar 23 | Apr 20–May 4 | 191 | two-plantings: Plant Apr 20 and again by Aug 15; both mature before Oct 28. | Aug 15 |
| Lavender | Jan 26 | Apr 20–May 4 | 226 | fits: 90 days to maturity, 226 available after Apr 20. | — |
| Marigolds | Mar 9 | Apr 20–Apr 27 | 191 | two-plantings: Plant Apr 20 and again by Aug 25; both mature before Oct 28. | Aug 25 |
| Melons | Apr 6 | May 4–May 11 | 163 | fits: 85 days to maturity, 163 available after May 4. | Jul 7 |
| Mint | — | Apr 20–May 4 | 226 | fits: 90 days to maturity, 226 available after Apr 20. | — |
| Nasturtiums | Mar 23 | Apr 20–Apr 27 | 191 | two-plantings: Plant Apr 20 and again by Aug 20; both mature before Oct 28. | Aug 20 |
| Pole Beans | — | Apr 27–May 11 | 184 | fits: 65 days to maturity, 184 available after Apr 27. | Aug 10 |
| Spaghetti Squash | Apr 6 | May 4–May 11 | 170 | fits: 90 days to maturity, 170 available after May 4. | Jul 9 |
| Sunflowers | — | Apr 20–May 4 | 191 | fits: 70 days to maturity, 191 available after Apr 20. | Aug 5 |
| Tomatillos | Feb 23 | Apr 27–May 4 | 170 | fits: 75 days to maturity, 170 available after Apr 27. | Jul 17 |
| Watermelon | Apr 6 | Apr 27–May 4 | 170 | fits: 80 days to maturity, 170 available after Apr 27. | Jul 12 |
| Yellow Squash | Apr 6 | May 4–May 11 | 177 | two-plantings: Plant May 4 and again by Aug 20; both mature before Oct 28. | Aug 20 |
| Zinnias | Mar 23 | Apr 20–May 4 | 191 | two-plantings: Plant Apr 20 and again by Aug 15; both mature before Oct 28. | Aug 15 |
Month by month in Oroville
| Month | What to do |
|---|---|
| January | Start indoors: Chives (Jan 26), Lavender (Jan 26), Onion (Jan 26), Rosemary (Jan 26). |
| February | Start indoors: Celery (Feb 9), Collards (Feb 9), Kale (Feb 9), Oregano (Feb 9), Parsley (Feb 9), Scallions (Feb 9), +8 more. Direct sow from: Arugula (Feb 23), Beets (Feb 23), Dill (Feb 23), Peas (Feb 23), Radish (Feb 23), Spinach (Feb 23). |
| March | Start indoors: Eggplant (Mar 2), Calendula (Mar 9), Cauliflower (Mar 9), Marigolds (Mar 9), Pepper (Mar 9), Basil (Mar 16), +8 more. Direct sow from: Kohlrabi (Mar 9), Cilantro (Mar 23), Turnip (Mar 23), Carrots (Mar 30). Transplant from: Broccoli (Mar 23), Brussel Sprouts (Mar 23), Cabbage (Mar 23), Collards (Mar 23), Kale (Mar 23), Lettuce (Mar 23), +2 more. Plant: Strawberry (Mar 16). |
| April | Start indoors: Butternut Squash (Apr 6), Cantaloupe (Apr 6), Melons (Apr 6), Pumpkin (Apr 6), Spaghetti Squash (Apr 6), Watermelon (Apr 6), +2 more. Direct sow from: Potatoes (Apr 6), Sunflowers (Apr 20), Beans (Apr 27), Pole Beans (Apr 27). Transplant from: Calendula (Apr 6), Swiss Chard (Apr 6), Bok Choy (Apr 13), Cauliflower (Apr 13), Cosmos (Apr 20), Lavender (Apr 20), +15 more. Last frost around April 20. |
| May | Transplant from: Butternut Squash (May 4), Cantaloupe (May 4), Cucumber (May 4), Eggplant (May 4), Melons (May 4), Pepper (May 4), +6 more. |
| June | Last sowing dates: Butternut Squash (Jun 29), Pumpkin (Jun 29). |
| July | Last sowing dates: Cantaloupe (Jul 7), Celery (Jul 7), Melons (Jul 7), Spaghetti Squash (Jul 9), Tomato (Jul 12), Watermelon (Jul 12), +4 more. |
| August | Last sowing dates: Sunflowers (Aug 5), Brussel Sprouts (Aug 10), Pole Beans (Aug 10), Basil (Aug 15), Cosmos (Aug 15), Cucumber (Aug 15), +11 more. |
| September | Last sowing dates: Cabbage (Sep 9), Carrots (Sep 9), Beets (Sep 10), Dill (Sep 10), Swiss Chard (Sep 10), Calendula (Sep 15), +8 more. |
| October | Last sowing dates: Arugula (Oct 9), Spinach (Oct 9), Radish (Oct 10). |
| November | Direct sow from: Garlic (Nov 11). First frost around November 11. |
| December | Last sowing dates: Garlic (Dec 2). |
Frequently Asked Questions
What is the last frost date for Oroville, CA (ZIP 95966)?
The median last spring frost date for Oroville, CA (ZIP code 95966) is around April 20. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before April 29; one in ten it runs past May 11.
What is the first fall frost date in Oroville, CA?
The median first fall frost date for Oroville, CA is around November 11. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around October 20 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Oroville, CA?
The frost-free growing season in Oroville is about 205 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Oroville (205 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Oroville, CA?
Oroville, CA is in USDA hardiness zone 9b (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Oroville, CA?
Start tomatoes indoors Mar 16 and plant out May 4 in Oroville. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Oroville?
Two: plant Mar 23 and again by Sep 20; both mature before Nov 18.
When do I plant garlic in Oroville?
Nov 11 to Dec 2; it overwinters and is ready the following summer.
Can I get two tomato crops in Oroville?
Yes: plant out May 4 for a summer crop, and set out a second round of transplants by Jul 12 for a fall crop.
Which nearby ZIP has a longer season?
Marysville (ZIP 95901) has 295 frost-free days, 90 more than Oroville (ZIP 95966). See Marysville ZIP 95901 frost dates
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