Frost dates for 95383Twain Harte, CA
The average last spring frost in Twain Harte is April 16 and the average first fall frost is November 12, giving a typical growing season of about 208 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 16
- Average first fall frost
- Nov 12
- Growing season
- 208 days
Safer after May 12 (1-in-10 risk)
Possible by Oct 24 (1-in-10 risk)
First frost typically in 14 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) | Apr 17 · May 5 · May 31 | Oct 11 · Oct 29 · Nov 12 | 172 days | 100% |
| Frost / freeze (32°F) | Mar 24 · Apr 16 · May 12 | Oct 24 · Nov 12 · Dec 1 | 208 days | 100% |
| Hard freeze (28°F) | Feb 19 · Mar 25 · Apr 17 | Nov 9 · Nov 28 · Dec 18 | 249 days | 100% |
Planting calendar for Twain Harte
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 | Mar 16 – May 22 |
| Tomatoes | Transplant outdoors | May 2 – Jul 23 |
| Peppers | Start seeds indoors | Mar 16 – Apr 16 |
| Peppers | Transplant outdoors | May 16 – Jun 16 |
| Eggplant | Start seeds indoors | Apr 2 – May 1 |
| Eggplant | Transplant outdoors | May 16 – Jun 16 |
| Cucumbers | Sow outdoors | May 16 – Aug 2 |
| Summer squash | Sow outdoors | May 2 – Jun 16 |
| Winter squash & pumpkins | Sow outdoors | May 16 – Jun 16 |
| Snap beans | Sow outdoors | May 2 – Aug 25 |
| Sweet corn | Sow outdoors | May 2 – Jul 23 |
| Watermelon & cantaloupe | Sow outdoors | May 16 – Jun 16 |
| Okra | Sow outdoors | May 9 – Jun 1 |
| Peas | Sow outdoors (spring) | Mar 16 – May 1 |
| Potatoes | Plant outdoors (spring) | Mar 16 – May 16 |
| Onions | Start seeds indoors (spring) | Feb 2 – Mar 1 |
| Onions | Transplant outdoors (spring) | Apr 2 – May 1 |
| Broccoli | Start seeds indoors (spring) | Feb 26 – Apr 1 |
| Broccoli | Transplant outdoors (spring) | Apr 2 – May 1 |
| Broccoli | Start seeds indoors (fall) | Jul 13 – Jul 23 |
| Broccoli | Transplant outdoors (fall) | Aug 12 – Aug 23 |
| Cabbage | Start seeds indoors (spring) | Feb 16 – Mar 16 |
| Cabbage | Transplant outdoors (spring) | Mar 16 – Apr 16 |
| Cabbage | Start seeds indoors (fall) | Jul 3 – Aug 2 |
| Cabbage | Transplant outdoors (fall) | Aug 2 – Sep 2 |
| Leaf lettuce | Sow outdoors (spring) | Mar 16 – Jun 1 |
| Leaf lettuce | Sow outdoors (fall) | Aug 2 – Sep 18 |
| Spinach | Sow outdoors (spring) | Mar 9 – Apr 22 |
| Spinach | Sow outdoors (fall) | Aug 19 – Sep 23 |
| Radishes | Sow outdoors (spring) | Mar 16 – May 6 |
| Radishes | Sow outdoors (fall) | Aug 2 – Oct 3 |
| Kale | Sow outdoors (spring) | Apr 2 – Apr 22 |
| Kale | Sow outdoors (fall) | Jul 26 – Sep 2 |
| Carrots | Sow outdoors (spring) | Apr 16 – Jun 1 |
| Carrots | Sow outdoors (fall) | Jul 3 – Aug 18 |
| Garlic | Plant outdoors (fall) | Nov 2 – Dec 3 |
Where these dates come from
ZIP code 95383 is matched to the NOAA station Hetch Hetchy, CA, 39.2 km away, at 3,870 ft elevation (264 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hetch Hetchy, CA (used) | 3,870 ft | Apr 16 | Nov 12 |
| Sonora, CA | 1,675 ft | Apr 9 | Nov 9 |
| Groveland 2, CA | 2,800 ft | Apr 22 | Nov 2 |
| New Melones Dam Hq, CA | 960 ft | Feb 20 | Dec 11 |
Frost dates near Twain Harte
- Mi Wuk Village, CA 95346 · last May 7, first Oct 28
- Soulsbyville, CA 95372 · last Apr 22, first Nov 2
- Tuolumne, CA 95379 · last Apr 22, first Nov 2
- Long Barn, CA 95335 · last May 2, first Nov 4
- Sonora, CA 95370 · last Apr 9, first Nov 9
- Standard, CA 95373 · last Apr 9, first Nov 9
- Columbia, CA 95310 · last Apr 9, first Nov 9
- Hathaway Pines, CA 95233 · last May 7, first Oct 28
Frequently asked questions
- When is the last frost in Twain Harte, CA?
- For ZIP code 95383, the average last spring frost (32°F) is April 16, based on NOAA 1991-2020 climate normals for the Hetch Hetchy, CA weather station. There is a 1-in-10 chance of a frost after May 12.
- When is the first frost in Twain Harte, CA?
- The average first fall frost (32°F) is November 12. There is a 1-in-10 chance of frost by October 24, so tender plants are at risk from that point on.
- How long is the growing season in 95383?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 208 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.