Frost dates for 81024Boncarbo, CO
The average last spring frost in Boncarbo is May 5 and the average first fall frost is October 9, giving a typical growing season of about 156 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 5
- Average first fall frost
- Oct 9
- Growing season
- 156 days
Safer after May 17 (1-in-10 risk)
Possible by Sep 25 (1-in-10 risk)
Last frost typically in 190 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 3 · May 16 · May 30 | Sep 19 · Oct 2 · Oct 14 | 137 days | 100% |
| Frost / freeze (32°F) | Apr 22 · May 5 · May 17 | Sep 25 · Oct 9 · Oct 22 | 156 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 25 · May 8 | Oct 2 · Oct 19 · Nov 2 | 174 days | 100% |
Planting calendar for Boncarbo
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 4 – Jun 10 |
| Tomatoes | Transplant outdoors | May 21 – Jun 19 |
| Peppers | Start seeds indoors | Apr 4 – May 5 |
| Peppers | Transplant outdoors | Jun 4 – Jul 5 |
| Eggplant | Start seeds indoors | Apr 21 – May 20 |
| Eggplant | Transplant outdoors | Jun 4 – Jul 5 |
| Cucumbers | Sow outdoors | Jun 4 – Jun 29 |
| Summer squash | Sow outdoors | May 21 – Jul 5 |
| Winter squash & pumpkins | Sow outdoors | Jun 4 – Jul 5 |
| Snap beans | Sow outdoors | May 21 – Jul 22 |
| Sweet corn | Sow outdoors | May 21 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 4 – Jul 5 |
| Okra | Sow outdoors | May 28 – Jun 20 |
| Peas | Sow outdoors (spring) | Apr 4 – May 20 |
| Potatoes | Plant outdoors (spring) | Apr 4 – Jun 4 |
| Onions | Start seeds indoors (spring) | Feb 21 – Mar 20 |
| Onions | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (spring) | Mar 17 – Apr 20 |
| Broccoli | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 7 – Apr 4 |
| Cabbage | Transplant outdoors (spring) | Apr 4 – May 5 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Apr 4 – Jun 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 28 – May 11 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Apr 4 – May 25 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 21 – May 11 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 5 – Jun 20 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 81024 is matched to the NOAA station Raton Fltr Plt, NM, 41 km away, at 6,932 ft elevation (95 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Raton Fltr Plt, NM (used) | 6,932 ft | May 5 | Oct 9 |
| Trinidad Lake, CO | 6,310 ft | May 11 | Oct 4 |
| Trinidad, CO | 6,030 ft | Apr 30 | Oct 15 |
| Trinidad Perry Stokes Ap, CO | 5,741 ft | May 4 | Oct 9 |
Frost dates near Boncarbo
- Weston, CO 81091 · last May 21, first Sep 29
- Trinidad, CO 81082 · last Apr 30, first Oct 15
- Aguilar, CO 81020 · last May 11, first Oct 4
- Hoehne, CO 81046 · last May 4, first Oct 9
- Raton, NM 87740 · last May 19, first Sep 29
- La Veta, CO 81055 · last May 27, first Sep 25
- Walsenburg, CO 81089 · last May 6, first Oct 4
- Trinchera, CO 81081 · last May 4, first Oct 9
Frequently asked questions
- When is the last frost in Boncarbo, CO?
- For ZIP code 81024, the average last spring frost (32°F) is May 5, based on NOAA 1991-2020 climate normals for the Raton Fltr Plt, NM weather station. There is a 1-in-10 chance of a frost after May 17.
- When is the first frost in Boncarbo, CO?
- The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 25, so tender plants are at risk from that point on.
- How long is the growing season in 81024?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 156 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.