Frost dates for 94975Petaluma, CA
The average last spring frost in Petaluma is February 28 and the average first fall frost is November 25, giving a typical growing season of about 271 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 28
- Average first fall frost
- Nov 25
- Growing season
- 271 days
Safer after Apr 6 (1-in-10 risk)
Possible by Nov 9 (1-in-10 risk)
First frost typically in 39 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 7 · Apr 6 · Apr 27 | Oct 27 · Nov 10 · Nov 28 | 218 days | 100% |
| Frost / freeze (32°F) | Jan 24 · Feb 28 · Apr 6 | Nov 9 · Nov 25 · Dec 16 | 271 days | 100% |
| Hard freeze (28°F) | Dec 17 · Jan 17 · Feb 24 | Nov 20 · Dec 9 · Jan 12 | 331 days | 88% |
Planting calendar for Petaluma
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 28 – Apr 5 |
| Tomatoes | Transplant outdoors | Mar 16 – Aug 5 |
| Peppers | Start seeds indoors | Jan 28 – Feb 28 |
| Peppers | Transplant outdoors | Mar 30 – Apr 30 |
| Eggplant | Start seeds indoors | Feb 14 – Mar 15 |
| Eggplant | Transplant outdoors | Mar 30 – Apr 30 |
| Cucumbers | Sow outdoors | Mar 30 – Aug 15 |
| Summer squash | Sow outdoors | Mar 16 – Apr 30 |
| Winter squash & pumpkins | Sow outdoors | Mar 30 – Apr 30 |
| Snap beans | Sow outdoors | Mar 16 – Sep 7 |
| Sweet corn | Sow outdoors | Mar 16 – Aug 5 |
| Watermelon & cantaloupe | Sow outdoors | Mar 30 – Apr 30 |
| Okra | Sow outdoors | Mar 23 – Apr 15 |
| Peas | Sow outdoors (spring) | Jan 28 – Mar 15 |
| Potatoes | Plant outdoors (spring) | Jan 28 – Mar 30 |
| Onions | Start seeds indoors (spring) | Dec 17 – Jan 13 |
| Onions | Transplant outdoors (spring) | Feb 14 – Mar 15 |
| Broccoli | Start seeds indoors (spring) | Jan 10 – Feb 13 |
| Broccoli | Transplant outdoors (spring) | Feb 14 – Mar 15 |
| Broccoli | Start seeds indoors (fall) | Jul 26 – Aug 5 |
| Broccoli | Transplant outdoors (fall) | Aug 25 – Sep 5 |
| Cabbage | Start seeds indoors (spring) | Dec 31 – Jan 28 |
| Cabbage | Transplant outdoors (spring) | Jan 28 – Feb 28 |
| Cabbage | Start seeds indoors (fall) | Jul 16 – Aug 15 |
| Cabbage | Transplant outdoors (fall) | Aug 15 – Sep 15 |
| Leaf lettuce | Sow outdoors (spring) | Jan 28 – Apr 15 |
| Leaf lettuce | Sow outdoors (fall) | Aug 15 – Oct 1 |
| Spinach | Sow outdoors (spring) | Jan 21 – Mar 6 |
| Spinach | Sow outdoors (fall) | Sep 1 – Oct 6 |
| Radishes | Sow outdoors (spring) | Jan 28 – Mar 20 |
| Radishes | Sow outdoors (fall) | Aug 15 – Oct 16 |
| Kale | Sow outdoors (spring) | Feb 14 – Mar 6 |
| Kale | Sow outdoors (fall) | Aug 8 – Sep 15 |
| Carrots | Sow outdoors (spring) | Feb 28 – Apr 15 |
| Carrots | Sow outdoors (fall) | Jul 16 – Aug 31 |
| Garlic | Plant outdoors (fall) | Nov 15 – Dec 16 |
Where these dates come from
ZIP code 94975 is matched to the NOAA station Petaluma Ap, CA, 3.8 km away, at 20 ft elevation (7 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Petaluma Ap, CA (used) | 20 ft | Feb 28 | Nov 25 |
| Sonoma, CA | 97 ft | Mar 2 | Nov 27 |
| Santa Rosa, CA | 166 ft | Feb 25 | Dec 1 |
| San Rafael Civic Ctr, CA | 120 ft | Jan 11 | Dec 21 |
Frost dates near Petaluma
- Petaluma, CA 94953 · last Feb 28, first Nov 25
- Penngrove, CA 94951 · last Feb 28, first Nov 25
- Novato, CA 94948 · last Feb 28, first Nov 25
- Cotati, CA 94931 · last Feb 28, first Nov 25
- Rohnert Park, CA 94926 · last Feb 25, first Dec 1
- El Verano, CA 95433 · last Mar 2, first Nov 27
- Sonoma, CA 95476 · last Mar 2, first Nov 27
- Boyes Hot Springs, CA 95416 · last Mar 2, first Nov 27
Frequently asked questions
- When is the last frost in Petaluma, CA?
- For ZIP code 94975, the average last spring frost (32°F) is February 28, based on NOAA 1991-2020 climate normals for the Petaluma Ap, CA weather station. There is a 1-in-10 chance of a frost after April 6.
- When is the first frost in Petaluma, CA?
- The average first fall frost (32°F) is November 25. There is a 1-in-10 chance of frost by November 9, so tender plants are at risk from that point on.
- How long is the growing season in 94975?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 271 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.