Frost Dates for Windsor, CA 95492
Last spring frost February 21 · First fall frost December 7 · 289 frost-free days · USDA Zone 9a
Frost probability for 95492
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | April 5 | February 21 | January 10 |
| Fall (first frost) | November 5 | December 7 | January 8 |
Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (12.0 km away); the 50% date is the median year.
Month by month in Windsor
| Month | What to do |
|---|---|
| January | Start herbs, basil, and squash indoors (4–6 weeks before frost). Direct sow peas, spinach, and lettuce if soil is workable. |
| February | Last frost around February 21. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings. |
| March | Frost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini. |
| April | Succession plant lettuce and greens. Keep beds weeded and watered consistently. |
| May | Harvest regularly to encourage production. Monitor for pests and disease. |
| June | Midsummer: harvest beans, zucchini, cucumbers. Start brassica seeds indoors for fall. |
| July | Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors. |
| August | Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors. |
| September | Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors. |
| October | Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors. |
| November | First fall frost approaching (around December 7). Transplant fall brassicas. Sow spinach, arugula, and radishes. |
| December | First frost around December 7. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season. |
What grows in a 289-day season
Frequently Asked Questions
What is the last frost date for Windsor, CA (ZIP 95492)?
The median last spring frost date for Windsor, CA (ZIP code 95492) is around February 21. 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.
What is the first fall frost date in Windsor, CA?
The median first fall frost date for Windsor, CA is around December 7. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses.
How long is the growing season in Windsor, CA?
The frost-free growing season in Windsor is about 289 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.
What USDA hardiness zone is Windsor, CA?
Based on frost date patterns, Windsor falls approximately in 9a. USDA hardiness zones are determined by average annual minimum winter temperatures and guide both plant selection and planting timing for your location.
When should I start tomatoes indoors in Windsor, CA?
Start tomato seeds indoors 6–8 weeks before your last frost date (around February 21). For Windsor, that's roughly December 27 to January 10. Transplant outdoors 1–2 weeks after your last frost.
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