Frost dates for 94515Calistoga, CA
The average last spring frost in Calistoga is March 2 and the average first fall frost is November 23, giving a typical growing season of about 263 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 2
- Average first fall frost
- Nov 23
- Growing season
- 263 days
Safer after Apr 18 (1-in-10 risk)
Possible by Nov 1 (1-in-10 risk)
First frost typically in 23 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 10 · Apr 13 · May 18 | Oct 13 · Nov 4 · Nov 27 | 203 days | 100% |
| Frost / freeze (32°F) | Jan 19 · Mar 2 · Apr 18 | Nov 1 · Nov 23 · Dec 20 | 263 days | 100% |
| Hard freeze (28°F) | Dec 12 · Jan 23 · Mar 6 | Nov 16 · Dec 6 · Jan 15 | 327 days | 87% |
Planting calendar for Calistoga
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 30 – Apr 7 |
| Tomatoes | Transplant outdoors | Mar 18 – Aug 3 |
| Peppers | Start seeds indoors | Jan 30 – Mar 2 |
| Peppers | Transplant outdoors | Apr 1 – May 2 |
| Eggplant | Start seeds indoors | Feb 16 – Mar 17 |
| Eggplant | Transplant outdoors | Apr 1 – May 2 |
| Cucumbers | Sow outdoors | Apr 1 – Aug 13 |
| Summer squash | Sow outdoors | Mar 18 – May 2 |
| Winter squash & pumpkins | Sow outdoors | Apr 1 – May 2 |
| Snap beans | Sow outdoors | Mar 18 – Sep 5 |
| Sweet corn | Sow outdoors | Mar 18 – Aug 3 |
| Watermelon & cantaloupe | Sow outdoors | Apr 1 – May 2 |
| Okra | Sow outdoors | Mar 25 – Apr 17 |
| Peas | Sow outdoors (spring) | Jan 30 – Mar 17 |
| Potatoes | Plant outdoors (spring) | Jan 30 – Apr 1 |
| Onions | Start seeds indoors (spring) | Dec 19 – Jan 15 |
| Onions | Transplant outdoors (spring) | Feb 16 – Mar 17 |
| Broccoli | Start seeds indoors (spring) | Jan 12 – Feb 15 |
| Broccoli | Transplant outdoors (spring) | Feb 16 – Mar 17 |
| Broccoli | Start seeds indoors (fall) | Jul 24 – Aug 3 |
| Broccoli | Transplant outdoors (fall) | Aug 23 – Sep 3 |
| Cabbage | Start seeds indoors (spring) | Jan 2 – Jan 30 |
| Cabbage | Transplant outdoors (spring) | Jan 30 – Mar 2 |
| Cabbage | Start seeds indoors (fall) | Jul 14 – Aug 13 |
| Cabbage | Transplant outdoors (fall) | Aug 13 – Sep 13 |
| Leaf lettuce | Sow outdoors (spring) | Jan 30 – Apr 17 |
| Leaf lettuce | Sow outdoors (fall) | Aug 13 – Sep 29 |
| Spinach | Sow outdoors (spring) | Jan 23 – Mar 8 |
| Spinach | Sow outdoors (fall) | Aug 30 – Oct 4 |
| Radishes | Sow outdoors (spring) | Jan 30 – Mar 22 |
| Radishes | Sow outdoors (fall) | Aug 13 – Oct 14 |
| Kale | Sow outdoors (spring) | Feb 16 – Mar 8 |
| Kale | Sow outdoors (fall) | Aug 6 – Sep 13 |
| Carrots | Sow outdoors (spring) | Mar 2 – Apr 17 |
| Carrots | Sow outdoors (fall) | Jul 14 – Aug 29 |
| Garlic | Plant outdoors (fall) | Nov 13 – Dec 14 |
Where these dates come from
ZIP code 94515 is matched to the NOAA station Calistoga, CA, 2.3 km away, at 400 ft elevation (39 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Calistoga, CA (used) | 400 ft | Mar 2 | Nov 23 |
| Angwin Pacific Union College, CA | 1,715 ft | Apr 7 | Dec 5 |
| Saint Helena, CA | 225 ft | Feb 3 | Dec 4 |
| Santa Rosa, CA | 166 ft | Feb 25 | Dec 1 |
Frost dates near Calistoga
- Deer Park, CA 94576 · last Mar 2, first Nov 23
- Angwin, CA 94508 · last Apr 7, first Dec 5
- Saint Helena, CA 94574 · last Feb 3, first Dec 4
- Pope Valley, CA 94567 · last Mar 2, first Nov 23
- Santa Rosa, CA 95409 · last Feb 25, first Dec 1
- Kenwood, CA 95452 · last Feb 3, first Dec 4
- Rutherford, CA 94573 · last Feb 3, first Dec 4
- Fulton, CA 95439 · last Mar 2, first Nov 20
Frequently asked questions
- When is the last frost in Calistoga, CA?
- For ZIP code 94515, the average last spring frost (32°F) is March 2, based on NOAA 1991-2020 climate normals for the Calistoga, CA weather station. There is a 1-in-10 chance of a frost after April 18.
- When is the first frost in Calistoga, CA?
- The average first fall frost (32°F) is November 23. There is a 1-in-10 chance of frost by November 1, so tender plants are at risk from that point on.
- How long is the growing season in 94515?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 263 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.