Frost dates for 81328Mancos, CO
The average last spring frost in Mancos is June 4 and the average first fall frost is September 24, giving a typical growing season of about 111 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 4
- Average first fall frost
- Sep 24
- Growing season
- 111 days
Safer after Jun 19 (1-in-10 risk)
Possible by Sep 9 (1-in-10 risk)
Last frost typically in 220 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) | Jun 2 · Jun 15 · Jun 30 | Sep 3 · Sep 15 · Sep 27 | 90 days | 100% |
| Frost / freeze (32°F) | May 20 · Jun 4 · Jun 19 | Sep 9 · Sep 24 · Oct 4 | 111 days | 100% |
| Hard freeze (28°F) | May 5 · May 21 · Jun 9 | Sep 17 · Oct 2 · Oct 15 | 132 days | 100% |
Planting calendar for Mancos
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 4 – Jul 10 |
| Tomatoes | Transplant outdoors | Jun 20 – Jun 4 |
| Peppers | Start seeds indoors | May 4 – Jun 4 |
| Peppers | Transplant outdoors | Jul 4 – Aug 4 |
| Eggplant | Start seeds indoors | May 21 – Jun 19 |
| Eggplant | Transplant outdoors | Jul 4 – Aug 4 |
| Cucumbers | Sow outdoors | Jul 4 – Jun 14 |
| Summer squash | Sow outdoors | Jun 20 – Aug 4 |
| Winter squash & pumpkins | Sow outdoors | Jul 4 – Aug 4 |
| Snap beans | Sow outdoors | Jun 20 – Jul 7 |
| Sweet corn | Sow outdoors | Jun 20 – Jun 4 |
| Watermelon & cantaloupe | Sow outdoors | Jul 4 – Aug 4 |
| Okra | Sow outdoors | Jun 27 – Jul 20 |
| Peas | Sow outdoors (spring) | May 4 – Jun 19 |
| Potatoes | Plant outdoors (spring) | May 4 – Jul 4 |
| Onions | Start seeds indoors (spring) | Mar 23 – Apr 19 |
| Onions | Transplant outdoors (spring) | May 21 – Jun 19 |
| Broccoli | Start seeds indoors (spring) | Apr 16 – May 20 |
| Broccoli | Transplant outdoors (spring) | May 21 – Jun 19 |
| Broccoli | Start seeds indoors (fall) | May 25 – Jun 4 |
| Broccoli | Transplant outdoors (fall) | Jun 24 – Jul 5 |
| Cabbage | Start seeds indoors (spring) | Apr 6 – May 4 |
| Cabbage | Transplant outdoors (spring) | May 4 – Jun 4 |
| Cabbage | Start seeds indoors (fall) | May 15 – Jun 14 |
| Cabbage | Transplant outdoors (fall) | Jun 14 – Jul 15 |
| Leaf lettuce | Sow outdoors (spring) | May 4 – Jul 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 14 – Jul 31 |
| Spinach | Sow outdoors (spring) | Apr 27 – Jun 10 |
| Spinach | Sow outdoors (fall) | Jul 1 – Aug 5 |
| Radishes | Sow outdoors (spring) | May 4 – Jun 24 |
| Radishes | Sow outdoors (fall) | Jun 14 – Aug 15 |
| Kale | Sow outdoors (spring) | May 21 – Jun 10 |
| Kale | Sow outdoors (fall) | Jun 7 – Jul 15 |
| Carrots | Sow outdoors (spring) | Jun 4 – Jul 20 |
| Carrots | Sow outdoors (fall) | May 15 – Jun 30 |
| Garlic | Plant outdoors (fall) | Sep 14 – Oct 15 |
Where these dates come from
ZIP code 81328 is matched to the NOAA station Mancos 1Sw, CO, 2.1 km away, at 6,897 ft elevation (91 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Mancos 1Sw, CO (used) | 6,897 ft | Jun 4 | Sep 24 |
| Cortez 8 Se, CO | 8,035 ft | May 6 | Oct 14 |
| Mesa Verde Np, CO | 7,142 ft | May 9 | Oct 14 |
| Ft Lewis, CO | 7,614 ft | Jun 1 | Sep 27 |
Frost dates near Mancos
- Dolores, CO 81323 · last May 9, first Oct 14
- Mesa Verde National Park, CO 81330 · last May 9, first Oct 14
- Cortez, CO 81321 · last May 12, first Oct 7
- Hesperus, CO 81326 · last Jun 4, first Sep 24
- Marvel, CO 81329 · last Jun 1, first Sep 27
- Lewis, CO 81327 · last May 17, first Oct 9
- Durango, CO 81302 · last May 21, first Oct 2
- Towaoc, CO 81334 · last May 27, first Sep 28
Frequently asked questions
- When is the last frost in Mancos, CO?
- For ZIP code 81328, the average last spring frost (32°F) is June 4, based on NOAA 1991-2020 climate normals for the Mancos 1Sw, CO weather station. There is a 1-in-10 chance of a frost after June 19.
- When is the first frost in Mancos, CO?
- The average first fall frost (32°F) is September 24. There is a 1-in-10 chance of frost by September 9, so tender plants are at risk from that point on.
- How long is the growing season in 81328?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 111 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.