Frost dates for 81652Silt, CO
The average last spring frost in Silt is May 11 and the average first fall frost is October 4, giving a typical growing season of about 143 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 11
- Average first fall frost
- Oct 4
- Growing season
- 143 days
Safer after May 27 (1-in-10 risk)
Possible by Sep 23 (1-in-10 risk)
Last frost typically in 196 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 12 · May 26 · Jun 8 | Sep 12 · Sep 25 · Oct 6 | 119 days | 100% |
| Frost / freeze (32°F) | Apr 28 · May 11 · May 27 | Sep 23 · Oct 4 · Oct 17 | 143 days | 100% |
| Hard freeze (28°F) | Apr 14 · Apr 28 · May 11 | Sep 30 · Oct 15 · Oct 27 | 167 days | 100% |
Planting calendar for Silt
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 10 – Jun 16 |
| Tomatoes | Transplant outdoors | May 27 – Jun 14 |
| Peppers | Start seeds indoors | Apr 10 – May 11 |
| Peppers | Transplant outdoors | Jun 10 – Jul 11 |
| Eggplant | Start seeds indoors | Apr 27 – May 26 |
| Eggplant | Transplant outdoors | Jun 10 – Jul 11 |
| Cucumbers | Sow outdoors | Jun 10 – Jun 24 |
| Summer squash | Sow outdoors | May 27 – Jul 11 |
| Winter squash & pumpkins | Sow outdoors | Jun 10 – Jul 11 |
| Snap beans | Sow outdoors | May 27 – Jul 17 |
| Sweet corn | Sow outdoors | May 27 – Jun 14 |
| Watermelon & cantaloupe | Sow outdoors | Jun 10 – Jul 11 |
| Okra | Sow outdoors | Jun 3 – Jun 26 |
| Peas | Sow outdoors (spring) | Apr 10 – May 26 |
| Potatoes | Plant outdoors (spring) | Apr 10 – Jun 10 |
| Onions | Start seeds indoors (spring) | Feb 27 – Mar 26 |
| Onions | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (spring) | Mar 23 – Apr 26 |
| Broccoli | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (fall) | Jun 4 – Jun 14 |
| Broccoli | Transplant outdoors (fall) | Jul 4 – Jul 15 |
| Cabbage | Start seeds indoors (spring) | Mar 13 – Apr 10 |
| Cabbage | Transplant outdoors (spring) | Apr 10 – May 11 |
| Cabbage | Start seeds indoors (fall) | May 25 – Jun 24 |
| Cabbage | Transplant outdoors (fall) | Jun 24 – Jul 25 |
| Leaf lettuce | Sow outdoors (spring) | Apr 10 – Jun 26 |
| Leaf lettuce | Sow outdoors (fall) | Jun 24 – Aug 10 |
| Spinach | Sow outdoors (spring) | Apr 3 – May 17 |
| Spinach | Sow outdoors (fall) | Jul 11 – Aug 15 |
| Radishes | Sow outdoors (spring) | Apr 10 – May 31 |
| Radishes | Sow outdoors (fall) | Jun 24 – Aug 25 |
| Kale | Sow outdoors (spring) | Apr 27 – May 17 |
| Kale | Sow outdoors (fall) | Jun 17 – Jul 25 |
| Carrots | Sow outdoors (spring) | May 11 – Jun 26 |
| Carrots | Sow outdoors (fall) | May 25 – Jul 10 |
| Garlic | Plant outdoors (fall) | Sep 24 – Oct 25 |
Where these dates come from
ZIP code 81652 is matched to the NOAA station Rifle Garfield Co Ap, CO, 5.8 km away, at 5,530 ft elevation (251 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Rifle Garfield Co Ap, CO (used) | 5,530 ft | May 11 | Oct 4 |
| Rifle 3Ene, CO | 5,469 ft | May 23 | Sep 25 |
| Glenwood Spgs #2, CO | 5,895 ft | May 13 | Oct 3 |
| Shoshone, CO | 5,992 ft | May 1 | Oct 14 |
Frost dates near Silt
- Rifle, CO 81650 · last May 11, first Oct 4
- New Castle, CO 81647 · last May 11, first Oct 4
- Glenwood Springs, CO 81601 · last May 13, first Oct 3
- Battlement Mesa, CO 81636 · last May 11, first Oct 4
- Parachute, CO 81635 · last May 11, first Oct 4
- Collbran, CO 81624 · last May 17, first Sep 30
- Carbondale, CO 81623 · last Jun 2, first Sep 23
- Molina, CO 81646 · last May 17, first Sep 30
Frequently asked questions
- When is the last frost in Silt, CO?
- For ZIP code 81652, the average last spring frost (32°F) is May 11, based on NOAA 1991-2020 climate normals for the Rifle Garfield Co Ap, CO weather station. There is a 1-in-10 chance of a frost after May 27.
- When is the first frost in Silt, CO?
- The average first fall frost (32°F) is October 4. There is a 1-in-10 chance of frost by September 23, so tender plants are at risk from that point on.
- How long is the growing season in 81652?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 143 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.