Frost dates for 81434Somerset, CO
The average last spring frost in Somerset is May 31 and the average first fall frost is September 23, giving a typical growing season of about 114 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 31
- Average first fall frost
- Sep 23
- Growing season
- 114 days
Safer after Jun 14 (1-in-10 risk)
Possible by Sep 11 (1-in-10 risk)
Last frost typically in 216 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 31 · Jun 12 · Jun 26 | Sep 1 · Sep 13 · Sep 24 | 90 days | 100% |
| Frost / freeze (32°F) | May 16 · May 31 · Jun 14 | Sep 11 · Sep 23 · Oct 3 | 114 days | 100% |
| Hard freeze (28°F) | Apr 29 · May 13 · Jun 1 | Sep 21 · Oct 2 · Oct 14 | 140 days | 100% |
Planting calendar for Somerset
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 30 – Jul 6 |
| Tomatoes | Transplant outdoors | Jun 16 – Jun 3 |
| Peppers | Start seeds indoors | Apr 30 – May 31 |
| Peppers | Transplant outdoors | Jun 30 – Jul 31 |
| Eggplant | Start seeds indoors | May 17 – Jun 15 |
| Eggplant | Transplant outdoors | Jun 30 – Jul 31 |
| Cucumbers | Sow outdoors | Jun 30 – Jun 13 |
| Summer squash | Sow outdoors | Jun 16 – Jul 31 |
| Winter squash & pumpkins | Sow outdoors | Jun 30 – Jul 31 |
| Snap beans | Sow outdoors | Jun 16 – Jul 6 |
| Sweet corn | Sow outdoors | Jun 16 – Jun 3 |
| Watermelon & cantaloupe | Sow outdoors | Jun 30 – Jul 31 |
| Okra | Sow outdoors | Jun 23 – Jul 16 |
| Peas | Sow outdoors (spring) | Apr 30 – Jun 15 |
| Potatoes | Plant outdoors (spring) | Apr 30 – Jun 30 |
| Onions | Start seeds indoors (spring) | Mar 19 – Apr 15 |
| Onions | Transplant outdoors (spring) | May 17 – Jun 15 |
| Broccoli | Start seeds indoors (spring) | Apr 12 – May 16 |
| Broccoli | Transplant outdoors (spring) | May 17 – Jun 15 |
| Broccoli | Start seeds indoors (fall) | May 24 – Jun 3 |
| Broccoli | Transplant outdoors (fall) | Jun 23 – Jul 4 |
| Cabbage | Start seeds indoors (spring) | Apr 2 – Apr 30 |
| Cabbage | Transplant outdoors (spring) | Apr 30 – May 31 |
| Cabbage | Start seeds indoors (fall) | May 14 – Jun 13 |
| Cabbage | Transplant outdoors (fall) | Jun 13 – Jul 14 |
| Leaf lettuce | Sow outdoors (spring) | Apr 30 – Jul 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 13 – Jul 30 |
| Spinach | Sow outdoors (spring) | Apr 23 – Jun 6 |
| Spinach | Sow outdoors (fall) | Jun 30 – Aug 4 |
| Radishes | Sow outdoors (spring) | Apr 30 – Jun 20 |
| Radishes | Sow outdoors (fall) | Jun 13 – Aug 14 |
| Kale | Sow outdoors (spring) | May 17 – Jun 6 |
| Kale | Sow outdoors (fall) | Jun 6 – Jul 14 |
| Carrots | Sow outdoors (spring) | May 31 – Jul 16 |
| Carrots | Sow outdoors (fall) | May 14 – Jun 29 |
| Garlic | Plant outdoors (fall) | Sep 13 – Oct 14 |
Where these dates come from
ZIP code 81434 is matched to the NOAA station Aspen Pitkin Co Ap, CO, 53.7 km away, at 7,721 ft elevation (335 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Aspen Pitkin Co Ap, CO (used) | 7,721 ft | May 31 | Sep 23 |
| Paonia 1Sw, CO | 5,581 ft | May 3 | Oct 12 |
| Crested Butte, CO | 8,868 ft | — | — |
| Cedaredge 3E, CO | 6,838 ft | May 3 | Oct 9 |
Frost dates near Somerset
- Paonia, CO 81428 · last May 3, first Oct 12
- Crawford, CO 81415 · last Jun 20, first Sep 10
- Hotchkiss, CO 81419 · last May 3, first Oct 12
- Crested Butte, CO 81225 · last —, first —
- Carbondale, CO 81623 · last Jun 2, first Sep 23
- Lazear, CO 81420 · last May 3, first Oct 12
- Snowmass, CO 81654 · last —, first —
- Cedaredge, CO 81413 · last May 3, first Oct 9
Frequently asked questions
- When is the last frost in Somerset, CO?
- For ZIP code 81434, the average last spring frost (32°F) is May 31, based on NOAA 1991-2020 climate normals for the Aspen Pitkin Co Ap, CO weather station. There is a 1-in-10 chance of a frost after June 14.
- When is the first frost in Somerset, CO?
- The average first fall frost (32°F) is September 23. There is a 1-in-10 chance of frost by September 11, so tender plants are at risk from that point on.
- How long is the growing season in 81434?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 114 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.