Frost dates for 92274Thermal, CA
The average last spring frost in Thermal is February 7 and the average first fall frost is December 2, giving a typical growing season of about 298 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 7
- Average first fall frost
- Dec 2
- Growing season
- 298 days
Safer after Mar 1 (1-in-10 risk)
Possible by Nov 16 (1-in-10 risk)
First frost typically in 36 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) | Feb 1 · Feb 28 · Mar 25 | Nov 5 · Nov 21 · Dec 5 | 266 days | 100% |
| Frost / freeze (32°F) | Jan 7 · Feb 7 · Mar 1 | Nov 16 · Dec 2 · Dec 21 | 298 days | 100% |
| Hard freeze (28°F) | Dec 18 · Jan 15 · Feb 16 | Nov 24 · Dec 13 · Jan 5 | 334 days | 88% |
Planting calendar for Thermal
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 7 – Mar 15 |
| Tomatoes | Transplant outdoors | Feb 23 – Aug 12 |
| Peppers | Start seeds indoors | Jan 7 – Feb 7 |
| Peppers | Transplant outdoors | Mar 9 – Apr 9 |
| Eggplant | Start seeds indoors | Jan 24 – Feb 22 |
| Eggplant | Transplant outdoors | Mar 9 – Apr 9 |
| Cucumbers | Sow outdoors | Mar 9 – Aug 22 |
| Summer squash | Sow outdoors | Feb 23 – Apr 9 |
| Winter squash & pumpkins | Sow outdoors | Mar 9 – Apr 9 |
| Snap beans | Sow outdoors | Feb 23 – Sep 14 |
| Sweet corn | Sow outdoors | Feb 23 – Aug 12 |
| Watermelon & cantaloupe | Sow outdoors | Mar 9 – Apr 9 |
| Okra | Sow outdoors | Mar 2 – Mar 25 |
| Peas | Sow outdoors (spring) | Jan 7 – Feb 22 |
| Potatoes | Plant outdoors (spring) | Jan 7 – Mar 9 |
| Onions | Start seeds indoors (spring) | Nov 26 – Dec 23 |
| Onions | Transplant outdoors (spring) | Jan 24 – Feb 22 |
| Broccoli | Start seeds indoors (spring) | Dec 20 – Jan 23 |
| Broccoli | Transplant outdoors (spring) | Jan 24 – Feb 22 |
| Broccoli | Start seeds indoors (fall) | Aug 2 – Aug 12 |
| Broccoli | Transplant outdoors (fall) | Sep 1 – Sep 12 |
| Cabbage | Start seeds indoors (spring) | Dec 10 – Jan 7 |
| Cabbage | Transplant outdoors (spring) | Jan 7 – Feb 7 |
| Cabbage | Start seeds indoors (fall) | Jul 23 – Aug 22 |
| Cabbage | Transplant outdoors (fall) | Aug 22 – Sep 22 |
| Leaf lettuce | Sow outdoors (spring) | Jan 7 – Mar 25 |
| Leaf lettuce | Sow outdoors (fall) | Aug 22 – Oct 8 |
| Spinach | Sow outdoors (spring) | Dec 31 – Feb 13 |
| Spinach | Sow outdoors (fall) | Sep 8 – Oct 13 |
| Radishes | Sow outdoors (spring) | Jan 7 – Feb 27 |
| Radishes | Sow outdoors (fall) | Aug 22 – Oct 23 |
| Kale | Sow outdoors (spring) | Jan 24 – Feb 13 |
| Kale | Sow outdoors (fall) | Aug 15 – Sep 22 |
| Carrots | Sow outdoors (spring) | Feb 7 – Mar 25 |
| Carrots | Sow outdoors (fall) | Jul 23 – Sep 7 |
| Garlic | Plant outdoors (fall) | Nov 22 – Dec 23 |
Where these dates come from
ZIP code 92274 is matched to the NOAA station Desert Resorts Rgnl Ap, CA, 7.7 km away, at -118 ft elevation (13 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Desert Resorts Rgnl Ap, CA (used) | -118 ft | Feb 7 | Dec 2 |
| Mecca Fire Stn, CA | -183 ft | Jan 6 | Dec 22 |
| Indio Fire Stn, CA | -21 ft | Dec 31 | Dec 27 |
| Borrego Desert Park, CA | 810 ft | Jan 10 | Jan 1 |
Frost dates near Thermal
- Mecca, CA 92254 · last Jan 6, first Dec 22
- Coachella, CA 92236 · last Feb 7, first Dec 2
- La Quinta, CA 92247 · last Feb 7, first Dec 2
- Indio, CA 92201 · last Feb 7, first Dec 2
- Indian Wells, CA 92210 · last Feb 7, first Dec 2
- Palm Desert, CA 92261 · last Jan 10, first Dec 23
- Salton City, CA 92275 · last Jan 6, first Dec 22
- Rancho Mirage, CA 92270 · last Jan 9, first Jan 9
Frequently asked questions
- When is the last frost in Thermal, CA?
- For ZIP code 92274, the average last spring frost (32°F) is February 7, based on NOAA 1991-2020 climate normals for the Desert Resorts Rgnl Ap, CA weather station. There is a 1-in-10 chance of a frost after March 1.
- When is the first frost in Thermal, CA?
- The average first fall frost (32°F) is December 2. There is a 1-in-10 chance of frost by November 16, so tender plants are at risk from that point on.
- How long is the growing season in 92274?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 298 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.