Frost dates for 80476Silver Plume, CO
The average last spring frost in Silver Plume is June 6 and the average first fall frost is September 19, giving a typical growing season of about 103 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 6
- Average first fall frost
- Sep 19
- Growing season
- 103 days
Safer after Jun 21 (1-in-10 risk)
Possible by Sep 5 (1-in-10 risk)
Last frost typically in 222 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 5 · Jun 19 · Jul 4 | Aug 17 · Sep 5 · Sep 19 | 77 days | 100% |
| Frost / freeze (32°F) | May 25 · Jun 6 · Jun 21 | Sep 5 · Sep 19 · Sep 30 | 103 days | 100% |
| Hard freeze (28°F) | May 11 · May 25 · Jun 9 | Sep 11 · Sep 26 · Oct 8 | 123 days | 100% |
Planting calendar for Silver Plume
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 6 – Jul 12 |
| Tomatoes | Transplant outdoors | Jun 22 – May 30 |
| Peppers | Start seeds indoors | May 6 – Jun 6 |
| Peppers | Transplant outdoors | Jul 6 – Aug 6 |
| Eggplant | Start seeds indoors | May 23 – Jun 21 |
| Eggplant | Transplant outdoors | Jul 6 – Aug 6 |
| Cucumbers | Sow outdoors | Jul 6 – Jun 9 |
| Summer squash | Sow outdoors | Jun 22 – Aug 6 |
| Winter squash & pumpkins | Sow outdoors | Jul 6 – Aug 6 |
| Snap beans | Sow outdoors | Jun 22 – Jul 2 |
| Sweet corn | Sow outdoors | Jun 22 – May 30 |
| Watermelon & cantaloupe | Sow outdoors | Jul 6 – Aug 6 |
| Okra | Sow outdoors | Jun 29 – Jul 22 |
| Peas | Sow outdoors (spring) | May 6 – Jun 21 |
| Potatoes | Plant outdoors (spring) | May 6 – Jul 6 |
| Onions | Start seeds indoors (spring) | Mar 25 – Apr 21 |
| Onions | Transplant outdoors (spring) | May 23 – Jun 21 |
| Broccoli | Start seeds indoors (spring) | Apr 18 – May 22 |
| Broccoli | Transplant outdoors (spring) | May 23 – Jun 21 |
| Broccoli | Start seeds indoors (fall) | May 20 – May 30 |
| Broccoli | Transplant outdoors (fall) | Jun 19 – Jun 30 |
| Cabbage | Start seeds indoors (spring) | Apr 8 – May 6 |
| Cabbage | Transplant outdoors (spring) | May 6 – Jun 6 |
| Cabbage | Start seeds indoors (fall) | May 10 – Jun 9 |
| Cabbage | Transplant outdoors (fall) | Jun 9 – Jul 10 |
| Leaf lettuce | Sow outdoors (spring) | May 6 – Jul 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 9 – Jul 26 |
| Spinach | Sow outdoors (spring) | Apr 29 – Jun 12 |
| Spinach | Sow outdoors (fall) | Jun 26 – Jul 31 |
| Radishes | Sow outdoors (spring) | May 6 – Jun 26 |
| Radishes | Sow outdoors (fall) | Jun 9 – Aug 10 |
| Kale | Sow outdoors (spring) | May 23 – Jun 12 |
| Kale | Sow outdoors (fall) | Jun 2 – Jul 10 |
| Carrots | Sow outdoors (spring) | Jun 6 – Jul 22 |
| Carrots | Sow outdoors (fall) | May 10 – Jun 25 |
| Garlic | Plant outdoors (fall) | Sep 9 – Oct 10 |
Where these dates come from
ZIP code 80476 is matched to the NOAA station Cabin Creek, CO, 6.1 km away, at 10,021 ft elevation (10 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cabin Creek, CO (used) | 10,021 ft | Jun 6 | Sep 19 |
| Georgetown, CO | 8,520 ft | May 30 | Sep 19 |
| Dillon 1 E, CO | 9,065 ft | — | — |
| Grant, CO | 8,675 ft | Jun 15 | Sep 9 |
Frost dates near Silver Plume
- Georgetown, CO 80444 · last May 30, first Sep 19
- Empire, CO 80438 · last May 30, first Sep 19
- Idaho Springs, CO 80452 · last Jun 6, first Sep 19
- Dumont, CO 80436 · last May 24, first Sep 23
- Winter Park, CO 80482 · last Jun 21, first Sep 2
- Dillon, CO 80435 · last —, first —
- Central City, CO 80427 · last May 30, first Sep 19
- Black Hawk, CO 80422 · last Jun 5, first Sep 16
Frequently asked questions
- When is the last frost in Silver Plume, CO?
- For ZIP code 80476, the average last spring frost (32°F) is June 6, based on NOAA 1991-2020 climate normals for the Cabin Creek, CO weather station. There is a 1-in-10 chance of a frost after June 21.
- When is the first frost in Silver Plume, CO?
- The average first fall frost (32°F) is September 19. There is a 1-in-10 chance of frost by September 5, so tender plants are at risk from that point on.
- How long is the growing season in 80476?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 103 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.