Frost dates for 95442Glen Ellen, CA
The average last spring frost in Glen Ellen is March 2 and the average first fall frost is November 27, giving a typical growing season of about 270 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 2
- Average first fall frost
- Nov 27
- Growing season
- 270 days
Safer after Apr 5 (1-in-10 risk)
Possible by Nov 6 (1-in-10 risk)
First frost typically in 26 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 14 · Apr 8 · Apr 29 | Oct 25 · Nov 8 · Nov 26 | 214 days | 100% |
| Frost / freeze (32°F) | Jan 27 · Mar 2 · Apr 5 | Nov 6 · Nov 27 · Dec 21 | 270 days | 100% |
| Hard freeze (28°F) | Dec 20 · Jan 20 · Feb 22 | Nov 24 · Dec 14 · Jan 17 | 334 days | 87% |
Planting calendar for Glen Ellen
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 7 |
| 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 17 |
| Summer squash | Sow outdoors | Mar 18 – May 2 |
| Winter squash & pumpkins | Sow outdoors | Apr 1 – May 2 |
| Snap beans | Sow outdoors | Mar 18 – Sep 9 |
| Sweet corn | Sow outdoors | Mar 18 – Aug 7 |
| 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 28 – Aug 7 |
| Broccoli | Transplant outdoors (fall) | Aug 27 – Sep 7 |
| Cabbage | Start seeds indoors (spring) | Jan 2 – Jan 30 |
| Cabbage | Transplant outdoors (spring) | Jan 30 – Mar 2 |
| Cabbage | Start seeds indoors (fall) | Jul 18 – Aug 17 |
| Cabbage | Transplant outdoors (fall) | Aug 17 – Sep 17 |
| Leaf lettuce | Sow outdoors (spring) | Jan 30 – Apr 17 |
| Leaf lettuce | Sow outdoors (fall) | Aug 17 – Oct 3 |
| Spinach | Sow outdoors (spring) | Jan 23 – Mar 8 |
| Spinach | Sow outdoors (fall) | Sep 3 – Oct 8 |
| Radishes | Sow outdoors (spring) | Jan 30 – Mar 22 |
| Radishes | Sow outdoors (fall) | Aug 17 – Oct 18 |
| Kale | Sow outdoors (spring) | Feb 16 – Mar 8 |
| Kale | Sow outdoors (fall) | Aug 10 – Sep 17 |
| Carrots | Sow outdoors (spring) | Mar 2 – Apr 17 |
| Carrots | Sow outdoors (fall) | Jul 18 – Sep 2 |
| Garlic | Plant outdoors (fall) | Nov 17 – Dec 18 |
Where these dates come from
ZIP code 95442 is matched to the NOAA station Sonoma, CA, 9 km away, at 97 ft elevation (333 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Sonoma, CA (used) | 97 ft | Mar 2 | Nov 27 |
| Petaluma Ap, CA | 20 ft | Feb 28 | Nov 25 |
| Saint Helena, CA | 225 ft | Feb 3 | Dec 4 |
| Santa Rosa, CA | 166 ft | Feb 25 | Dec 1 |
Frost dates near Glen Ellen
- Eldridge, CA 95431 · last Mar 2, first Nov 27
- Kenwood, CA 95452 · last Feb 3, first Dec 4
- Boyes Hot Springs, CA 95416 · last Mar 2, first Nov 27
- El Verano, CA 95433 · last Mar 2, first Nov 27
- Sonoma, CA 95476 · last Mar 2, first Nov 27
- Penngrove, CA 94951 · last Feb 28, first Nov 25
- Vineburg, CA 95487 · last Mar 2, first Nov 27
- Oakville, CA 94562 · last Feb 3, first Dec 4
Frequently asked questions
- When is the last frost in Glen Ellen, CA?
- For ZIP code 95442, the average last spring frost (32°F) is March 2, based on NOAA 1991-2020 climate normals for the Sonoma, CA weather station. There is a 1-in-10 chance of a frost after April 5.
- When is the first frost in Glen Ellen, CA?
- The average first fall frost (32°F) is November 27. There is a 1-in-10 chance of frost by November 6, so tender plants are at risk from that point on.
- How long is the growing season in 95442?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 270 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.