Frost dates for 81038Fort Lyon, CO
The average last spring frost in Fort Lyon is April 29 and the average first fall frost is October 12, giving a typical growing season of about 166 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 12
- Growing season
- 166 days
Safer after May 11 (1-in-10 risk)
Possible by Oct 2 (1-in-10 risk)
Last frost typically in 184 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 25 · May 8 · May 22 | Sep 23 · Oct 5 · Oct 14 | 148 days | 100% |
| Frost / freeze (32°F) | Apr 15 · Apr 29 · May 11 | Oct 2 · Oct 12 · Oct 23 | 166 days | 100% |
| Hard freeze (28°F) | Apr 3 · Apr 18 · May 2 | Oct 8 · Oct 21 · Nov 1 | 185 days | 100% |
Planting calendar for Fort Lyon
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 29 – Jun 4 |
| Tomatoes | Transplant outdoors | May 15 – Jun 22 |
| Peppers | Start seeds indoors | Mar 29 – Apr 29 |
| Peppers | Transplant outdoors | May 29 – Jun 29 |
| Eggplant | Start seeds indoors | Apr 15 – May 14 |
| Eggplant | Transplant outdoors | May 29 – Jun 29 |
| Cucumbers | Sow outdoors | May 29 – Jul 2 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 25 |
| Sweet corn | Sow outdoors | May 15 – Jun 22 |
| Watermelon & cantaloupe | Sow outdoors | May 29 – Jun 29 |
| Okra | Sow outdoors | May 22 – Jun 14 |
| Peas | Sow outdoors (spring) | Mar 29 – May 14 |
| Potatoes | Plant outdoors (spring) | Mar 29 – May 29 |
| Onions | Start seeds indoors (spring) | Feb 15 – Mar 14 |
| Onions | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (spring) | Mar 11 – Apr 14 |
| Broccoli | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (fall) | Jun 12 – Jun 22 |
| Broccoli | Transplant outdoors (fall) | Jul 12 – Jul 23 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | Jun 2 – Jul 2 |
| Cabbage | Transplant outdoors (fall) | Jul 2 – Aug 2 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jul 2 – Aug 18 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 19 – Aug 23 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jul 2 – Sep 2 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 25 – Aug 2 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | Jun 2 – Jul 18 |
| Garlic | Plant outdoors (fall) | Oct 2 – Nov 2 |
Where these dates come from
ZIP code 81038 is matched to the NOAA station Las Animas, CO, 17.3 km away, at 3,890 ft elevation (132 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Las Animas, CO (used) | 3,890 ft | Apr 29 | Oct 12 |
| John Martin Dam, CO | 3,814 ft | Apr 24 | Oct 15 |
| Lamar Muni Ap, CO | 3,704 ft | May 2 | Oct 7 |
| La Junta Muni Ap, CO | 4,194 ft | Apr 24 | Oct 15 |
Frost dates near Fort Lyon
- Las Animas, CO 81054 · last Apr 29, first Oct 12
- Hasty, CO 81044 · last Apr 24, first Oct 15
- Mc Clave, CO 81057 · last Apr 24, first Oct 15
- Wiley, CO 81092 · last May 2, first Oct 7
- Cheraw, CO 81030 · last Apr 30, first Oct 10
- Lamar, CO 81052 · last Apr 30, first Oct 10
- Swink, CO 81077 · last May 1, first Oct 8
- La Junta, CO 81050 · last May 1, first Oct 8
Frequently asked questions
- When is the last frost in Fort Lyon, CO?
- For ZIP code 81038, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Las Animas, CO weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Fort Lyon, CO?
- The average first fall frost (32°F) is October 12. There is a 1-in-10 chance of frost by October 2, so tender plants are at risk from that point on.
- How long is the growing season in 81038?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 166 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.