Frost dates for 96101Alturas, CA
The average last spring frost in Alturas is June 3 and the average first fall frost is September 13, giving a typical growing season of about 97 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 3
- Average first fall frost
- Sep 13
- Growing season
- 97 days
Safer after Jun 26 (1-in-10 risk)
Possible by Aug 27 (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) | — | — | 62 days | 100% |
| Frost / freeze (32°F) | May 15 · Jun 3 · Jun 26 | Aug 27 · Sep 13 · Sep 28 | 97 days | 100% |
| Hard freeze (28°F) | Apr 26 · May 14 · Jun 5 | Sep 11 · Sep 27 · Oct 16 | 134 days | 100% |
Planting calendar for Alturas
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 | May 3 – Jul 9 |
| Tomatoes | Transplant outdoors | Jun 19 – May 24 |
| Peppers | Start seeds indoors | May 3 – Jun 3 |
| Peppers | Transplant outdoors | Jul 3 – Aug 3 |
| Eggplant | Start seeds indoors | May 20 – Jun 18 |
| Eggplant | Transplant outdoors | Jul 3 – Aug 3 |
| Cucumbers | Sow outdoors | Jul 3 – Jun 3 |
| Summer squash | Sow outdoors | Jun 19 – Aug 3 |
| Winter squash & pumpkins | Sow outdoors | Jul 3 – Aug 3 |
| Snap beans | Sow outdoors | Jun 19 – Jun 26 |
| Sweet corn | Sow outdoors | Jun 19 – May 24 |
| Watermelon & cantaloupe | Sow outdoors | Jul 3 – Aug 3 |
| Okra | Sow outdoors | Jun 26 – Jul 19 |
| Peas | Sow outdoors (spring) | May 3 – Jun 18 |
| Potatoes | Plant outdoors (spring) | May 3 – Jul 3 |
| Onions | Start seeds indoors (spring) | Mar 22 – Apr 18 |
| Onions | Transplant outdoors (spring) | May 20 – Jun 18 |
| Broccoli | Start seeds indoors (spring) | Apr 15 – May 19 |
| Broccoli | Transplant outdoors (spring) | May 20 – Jun 18 |
| Broccoli | Start seeds indoors (fall) | May 14 – May 24 |
| Broccoli | Transplant outdoors (fall) | Jun 13 – Jun 24 |
| Cabbage | Start seeds indoors (spring) | Apr 5 – May 3 |
| Cabbage | Transplant outdoors (spring) | May 3 – Jun 3 |
| Cabbage | Start seeds indoors (fall) | May 4 – Jun 3 |
| Cabbage | Transplant outdoors (fall) | Jun 3 – Jul 4 |
| Leaf lettuce | Sow outdoors (spring) | May 3 – Jul 19 |
| Leaf lettuce | Sow outdoors (fall) | Jun 3 – Jul 20 |
| Spinach | Sow outdoors (spring) | Apr 26 – Jun 9 |
| Spinach | Sow outdoors (fall) | Jun 20 – Jul 25 |
| Radishes | Sow outdoors (spring) | May 3 – Jun 23 |
| Radishes | Sow outdoors (fall) | Jun 3 – Aug 4 |
| Kale | Sow outdoors (spring) | May 20 – Jun 9 |
| Kale | Sow outdoors (fall) | May 27 – Jul 4 |
| Carrots | Sow outdoors (spring) | Jun 3 – Jul 19 |
| Carrots | Sow outdoors (fall) | May 4 – Jun 19 |
| Garlic | Plant outdoors (fall) | Sep 3 – Oct 4 |
Where these dates come from
ZIP code 96101 is matched to the NOAA station Alturas, CA, 1.5 km away, at 4,378 ft elevation (21 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Alturas, CA (used) | 4,378 ft | Jun 3 | Sep 13 |
| Alturas Muni Ap, CA | 4,375 ft | Jun 3 | Sep 12 |
| Canby 3 Sw, CA | 4,310 ft | Jun 1 | Sep 16 |
| Cedarville, CA | 4,688 ft | May 15 | Oct 1 |
Frost dates near Alturas
- Likely, CA 96116 · last Jun 3, first Sep 13
- Canby, CA 96015 · last Jun 1, first Sep 16
- Davis Creek, CA 96108 · last May 26, first Oct 1
- Cedarville, CA 96104 · last May 15, first Oct 1
- Lake City, CA 96115 · last May 15, first Oct 1
- Eagleville, CA 96110 · last May 15, first Oct 1
- Adin, CA 96006 · last May 28, first Sep 29
- Fort Bidwell, CA 96112 · last May 26, first Oct 1
Frequently asked questions
- When is the last frost in Alturas, CA?
- For ZIP code 96101, the average last spring frost (32°F) is June 3, based on NOAA 1991-2020 climate normals for the Alturas, CA weather station. There is a 1-in-10 chance of a frost after June 26.
- When is the first frost in Alturas, CA?
- The average first fall frost (32°F) is September 13. There is a 1-in-10 chance of frost by August 27, so tender plants are at risk from that point on.
- How long is the growing season in 96101?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 97 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.