Frost dates for 95405Santa Rosa, CA
The average last spring frost in Santa Rosa is February 25 and the average first fall frost is December 1, giving a typical growing season of about 279 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 25
- Average first fall frost
- Dec 1
- Growing season
- 279 days
Safer after Mar 29 (1-in-10 risk)
Possible by Nov 10 (1-in-10 risk)
First frost typically in 36 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Mar 6 · Apr 3 · Apr 25 | Oct 31 · Nov 14 · Dec 1 | 223 days | 100% |
| Frost / freeze (32°F) | Jan 21 · Feb 25 · Mar 29 | Nov 10 · Dec 1 · Dec 24 | 279 days | 99% |
| Hard freeze (28°F) | Dec 22 · Jan 20 · Feb 24 | Nov 26 · Dec 16 · Jan 19 | 335 days | 83% |
Planting calendar for Santa Rosa
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Jan 25 – Apr 2 |
| Tomatoes | Transplant outdoors | Mar 13 – Aug 11 |
| Peppers | Start seeds indoors | Jan 25 – Feb 25 |
| Peppers | Transplant outdoors | Mar 27 – Apr 27 |
| Eggplant | Start seeds indoors | Feb 11 – Mar 12 |
| Eggplant | Transplant outdoors | Mar 27 – Apr 27 |
| Cucumbers | Sow outdoors | Mar 27 – Aug 21 |
| Summer squash | Sow outdoors | Mar 13 – Apr 27 |
| Winter squash & pumpkins | Sow outdoors | Mar 27 – Apr 27 |
| Snap beans | Sow outdoors | Mar 13 – Sep 13 |
| Sweet corn | Sow outdoors | Mar 13 – Aug 11 |
| Watermelon & cantaloupe | Sow outdoors | Mar 27 – Apr 27 |
| Okra | Sow outdoors | Mar 20 – Apr 12 |
| Peas | Sow outdoors (spring) | Jan 25 – Mar 12 |
| Potatoes | Plant outdoors (spring) | Jan 25 – Mar 27 |
| Onions | Start seeds indoors (spring) | Dec 14 – Jan 10 |
| Onions | Transplant outdoors (spring) | Feb 11 – Mar 12 |
| Broccoli | Start seeds indoors (spring) | Jan 7 – Feb 10 |
| Broccoli | Transplant outdoors (spring) | Feb 11 – Mar 12 |
| Broccoli | Start seeds indoors (fall) | Aug 1 – Aug 11 |
| Broccoli | Transplant outdoors (fall) | Aug 31 – Sep 11 |
| Cabbage | Start seeds indoors (spring) | Dec 28 – Jan 25 |
| Cabbage | Transplant outdoors (spring) | Jan 25 – Feb 25 |
| Cabbage | Start seeds indoors (fall) | Jul 22 – Aug 21 |
| Cabbage | Transplant outdoors (fall) | Aug 21 – Sep 21 |
| Leaf lettuce | Sow outdoors (spring) | Jan 25 – Apr 12 |
| Leaf lettuce | Sow outdoors (fall) | Aug 21 – Oct 7 |
| Spinach | Sow outdoors (spring) | Jan 18 – Mar 3 |
| Spinach | Sow outdoors (fall) | Sep 7 – Oct 12 |
| Radishes | Sow outdoors (spring) | Jan 25 – Mar 17 |
| Radishes | Sow outdoors (fall) | Aug 21 – Oct 22 |
| Kale | Sow outdoors (spring) | Feb 11 – Mar 3 |
| Kale | Sow outdoors (fall) | Aug 14 – Sep 21 |
| Carrots | Sow outdoors (spring) | Feb 25 – Apr 12 |
| Carrots | Sow outdoors (fall) | Jul 22 – Sep 6 |
| Garlic | Plant outdoors (fall) | Nov 21 – Dec 22 |
Where these dates come from
ZIP code 95405 is matched to the NOAA station Santa Rosa, CA, 4 km away, at 166 ft elevation (54 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Santa Rosa, CA (used) | 166 ft | Feb 25 | Dec 1 |
| Santa Rosa Sonoma Co Ap, CA | 114 ft | Mar 2 | Nov 20 |
| Graton, CA | 200 ft | Mar 20 | Nov 13 |
| Calistoga, CA | 400 ft | Mar 2 | Nov 23 |
Frost dates near Santa Rosa
- Santa Rosa, CA 95402 · last Feb 25, first Dec 1
- Rohnert Park, CA 94928 · last Feb 25, first Dec 1
- Kenwood, CA 95452 · last Feb 3, first Dec 4
- Fulton, CA 95439 · last Mar 2, first Nov 20
- Cotati, CA 94931 · last Feb 28, first Nov 25
- Sebastopol, CA 95473 · last Mar 20, first Nov 13
- Penngrove, CA 94951 · last Feb 28, first Nov 25
- Glen Ellen, CA 95442 · last Mar 2, first Nov 27
Frequently asked questions
- When is the last frost in Santa Rosa, CA?
- For ZIP code 95405, the average last spring frost (32°F) is February 25, based on NOAA 1991-2020 climate normals for the Santa Rosa, CA weather station. There is a 1-in-10 chance of a frost after March 29.
- When is the first frost in Santa Rosa, CA?
- The average first fall frost (32°F) is December 1. There is a 1-in-10 chance of frost by November 10, so tender plants are at risk from that point on.
- How long is the growing season in 95405?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 279 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.