Frost dates for 96020Chester, CA
The average last spring frost in Chester is May 28 and the average first fall frost is September 28, giving a typical growing season of about 124 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 28
- Average first fall frost
- Sep 28
- Growing season
- 124 days
Safer after Jun 13 (1-in-10 risk)
Possible by Sep 12 (1-in-10 risk)
Last frost typically in 213 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) | May 31 · Jun 15 · Jul 2 | Aug 27 · Sep 12 · Sep 26 | 89 days | 100% |
| Frost / freeze (32°F) | May 7 · May 28 · Jun 13 | Sep 12 · Sep 28 · Oct 14 | 124 days | 100% |
| Hard freeze (28°F) | Apr 17 · May 2 · May 24 | Oct 1 · Oct 18 · Nov 1 | 163 days | 100% |
Planting calendar for Chester
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 | Apr 27 – Jul 3 |
| Tomatoes | Transplant outdoors | Jun 13 – Jun 8 |
| Peppers | Start seeds indoors | Apr 27 – May 28 |
| Peppers | Transplant outdoors | Jun 27 – Jul 28 |
| Eggplant | Start seeds indoors | May 14 – Jun 12 |
| Eggplant | Transplant outdoors | Jun 27 – Jul 28 |
| Cucumbers | Sow outdoors | Jun 27 – Jun 18 |
| Summer squash | Sow outdoors | Jun 13 – Jul 28 |
| Winter squash & pumpkins | Sow outdoors | Jun 27 – Jul 28 |
| Snap beans | Sow outdoors | Jun 13 – Jul 11 |
| Sweet corn | Sow outdoors | Jun 13 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 27 – Jul 28 |
| Okra | Sow outdoors | Jun 20 – Jul 13 |
| Peas | Sow outdoors (spring) | Apr 27 – Jun 12 |
| Potatoes | Plant outdoors (spring) | Apr 27 – Jun 27 |
| Onions | Start seeds indoors (spring) | Mar 16 – Apr 12 |
| Onions | Transplant outdoors (spring) | May 14 – Jun 12 |
| Broccoli | Start seeds indoors (spring) | Apr 9 – May 13 |
| Broccoli | Transplant outdoors (spring) | May 14 – Jun 12 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 30 – Apr 27 |
| Cabbage | Transplant outdoors (spring) | Apr 27 – May 28 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 27 – Jul 13 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 20 – Jun 3 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 27 – Jun 17 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | May 14 – Jun 3 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 28 – Jul 13 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 96020 is matched to the NOAA station Chester, CA, 1.4 km away, at 4,530 ft elevation (15 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Chester, CA (used) | 4,530 ft | May 28 | Sep 28 |
| Canyon Dam, CA | 4,560 ft | May 18 | Oct 8 |
| Mineral, CA | 4,875 ft | Jun 10 | Sep 13 |
| Manzanita Lake, CA | 5,750 ft | Jun 9 | Sep 21 |
Frost dates near Chester
- Westwood, CA 96137 · last May 18, first Oct 8
- Mill Creek, CA 96061 · last Jun 10, first Sep 13
- Twain, CA 95984 · last May 18, first Oct 8
- Mineral, CA 96063 · last Jun 10, first Sep 13
- Greenville, CA 95947 · last May 18, first Oct 8
- Belden, CA 95915 · last Apr 17, first Nov 11
- Crescent Mills, CA 95934 · last May 18, first Oct 8
- Old Station, CA 96071 · last Jun 10, first Sep 13
Frequently asked questions
- When is the last frost in Chester, CA?
- For ZIP code 96020, the average last spring frost (32°F) is May 28, based on NOAA 1991-2020 climate normals for the Chester, CA weather station. There is a 1-in-10 chance of a frost after June 13.
- When is the first frost in Chester, CA?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 12, so tender plants are at risk from that point on.
- How long is the growing season in 96020?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 124 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.