Frost dates for 80820Guffey, CO
The average last spring frost in Guffey is June 2 and the average first fall frost is September 19, giving a typical growing season of about 108 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 2
- Average first fall frost
- Sep 19
- Growing season
- 108 days
Safer after Jun 17 (1-in-10 risk)
Possible by Sep 6 (1-in-10 risk)
Last frost typically in 218 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 4 · Jun 16 · Jul 3 | Aug 30 · Sep 10 · Sep 21 | 83 days | 100% |
| Frost / freeze (32°F) | May 19 · Jun 2 · Jun 17 | Sep 6 · Sep 19 · Sep 30 | 108 days | 100% |
| Hard freeze (28°F) | May 7 · May 19 · Jun 2 | Sep 16 · Sep 29 · Oct 12 | 132 days | 100% |
Planting calendar for Guffey
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 2 – Jul 8 |
| Tomatoes | Transplant outdoors | Jun 18 – May 30 |
| Peppers | Start seeds indoors | May 2 – Jun 2 |
| Peppers | Transplant outdoors | Jul 2 – Aug 2 |
| Eggplant | Start seeds indoors | May 19 – Jun 17 |
| Eggplant | Transplant outdoors | Jul 2 – Aug 2 |
| Cucumbers | Sow outdoors | Jul 2 – Jun 9 |
| Summer squash | Sow outdoors | Jun 18 – Aug 2 |
| Winter squash & pumpkins | Sow outdoors | Jul 2 – Aug 2 |
| Snap beans | Sow outdoors | Jun 18 – Jul 2 |
| Sweet corn | Sow outdoors | Jun 18 – May 30 |
| Watermelon & cantaloupe | Sow outdoors | Jul 2 – Aug 2 |
| Okra | Sow outdoors | Jun 25 – Jul 18 |
| Peas | Sow outdoors (spring) | May 2 – Jun 17 |
| Potatoes | Plant outdoors (spring) | May 2 – Jul 2 |
| Onions | Start seeds indoors (spring) | Mar 21 – Apr 17 |
| Onions | Transplant outdoors (spring) | May 19 – Jun 17 |
| Broccoli | Start seeds indoors (spring) | Apr 14 – May 18 |
| Broccoli | Transplant outdoors (spring) | May 19 – Jun 17 |
| Broccoli | Start seeds indoors (fall) | May 20 – May 30 |
| Broccoli | Transplant outdoors (fall) | Jun 19 – Jun 30 |
| Cabbage | Start seeds indoors (spring) | Apr 4 – May 2 |
| Cabbage | Transplant outdoors (spring) | May 2 – Jun 2 |
| Cabbage | Start seeds indoors (fall) | May 10 – Jun 9 |
| Cabbage | Transplant outdoors (fall) | Jun 9 – Jul 10 |
| Leaf lettuce | Sow outdoors (spring) | May 2 – Jul 18 |
| Leaf lettuce | Sow outdoors (fall) | Jun 9 – Jul 26 |
| Spinach | Sow outdoors (spring) | Apr 25 – Jun 8 |
| Spinach | Sow outdoors (fall) | Jun 26 – Jul 31 |
| Radishes | Sow outdoors (spring) | May 2 – Jun 22 |
| Radishes | Sow outdoors (fall) | Jun 9 – Aug 10 |
| Kale | Sow outdoors (spring) | May 19 – Jun 8 |
| Kale | Sow outdoors (fall) | Jun 2 – Jul 10 |
| Carrots | Sow outdoors (spring) | Jun 2 – Jul 18 |
| Carrots | Sow outdoors (fall) | May 10 – Jun 25 |
| Garlic | Plant outdoors (fall) | Sep 9 – Oct 10 |
Where these dates come from
ZIP code 80820 is matched to the NOAA station Lake George 8 Sw, CO, 13.9 km away, at 8,550 ft elevation (1,253 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Lake George 8 Sw, CO (used) | 8,550 ft | Jun 2 | Sep 19 |
| Guffey 9Se, CO | 8,915 ft | May 19 | Oct 2 |
| Florissant Fossil Bed, CO | 8,402 ft | — | — |
| Cripple Creek 3Nnw, CO | 9,235 ft | May 26 | Sep 26 |
Frost dates near Guffey
- Florissant, CO 80816 · last —, first —
- Lake George, CO 80827 · last Jun 2, first Sep 19
- Hartsel, CO 80449 · last —, first —
- Divide, CO 80814 · last Jun 1, first Sep 21
- Cripple Creek, CO 80813 · last May 26, first Sep 26
- Canon City, CO 81215 · last May 29, first Sep 20
- Victor, CO 80860 · last May 26, first Sep 26
- Como, CO 80432 · last —, first —
Frequently asked questions
- When is the last frost in Guffey, CO?
- For ZIP code 80820, the average last spring frost (32°F) is June 2, based on NOAA 1991-2020 climate normals for the Lake George 8 Sw, CO weather station. There is a 1-in-10 chance of a frost after June 17.
- When is the first frost in Guffey, CO?
- The average first fall frost (32°F) is September 19. There is a 1-in-10 chance of frost by September 6, so tender plants are at risk from that point on.
- How long is the growing season in 80820?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 108 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.