Frost dates for 80517Estes Park, CO
The average last spring frost in Estes Park is May 30 and the average first fall frost is September 17, giving a typical growing season of about 109 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 30
- Average first fall frost
- Sep 17
- Growing season
- 109 days
Safer after Jun 14 (1-in-10 risk)
Possible by Sep 3 (1-in-10 risk)
Last frost typically in 215 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 29 · Jun 12 · Jun 28 | Aug 23 · Sep 6 · Sep 20 | 84 days | 100% |
| Frost / freeze (32°F) | May 15 · May 30 · Jun 14 | Sep 3 · Sep 17 · Oct 1 | 109 days | 100% |
| Hard freeze (28°F) | May 3 · May 16 · May 31 | Sep 12 · Sep 28 · Oct 12 | 134 days | 100% |
Planting calendar for Estes Park
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 29 – Jul 5 |
| Tomatoes | Transplant outdoors | Jun 15 – May 28 |
| Peppers | Start seeds indoors | Apr 29 – May 30 |
| Peppers | Transplant outdoors | Jun 29 – Jul 30 |
| Eggplant | Start seeds indoors | May 16 – Jun 14 |
| Eggplant | Transplant outdoors | Jun 29 – Jul 30 |
| Cucumbers | Sow outdoors | Jun 29 – Jun 7 |
| Summer squash | Sow outdoors | Jun 15 – Jul 30 |
| Winter squash & pumpkins | Sow outdoors | Jun 29 – Jul 30 |
| Snap beans | Sow outdoors | Jun 15 – Jun 30 |
| Sweet corn | Sow outdoors | Jun 15 – May 28 |
| Watermelon & cantaloupe | Sow outdoors | Jun 29 – Jul 30 |
| Okra | Sow outdoors | Jun 22 – Jul 15 |
| Peas | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Potatoes | Plant outdoors (spring) | Apr 29 – Jun 29 |
| Onions | Start seeds indoors (spring) | Mar 18 – Apr 14 |
| Onions | Transplant outdoors (spring) | May 16 – Jun 14 |
| Broccoli | Start seeds indoors (spring) | Apr 11 – May 15 |
| Broccoli | Transplant outdoors (spring) | May 16 – Jun 14 |
| Broccoli | Start seeds indoors (fall) | May 18 – May 28 |
| Broccoli | Transplant outdoors (fall) | Jun 17 – Jun 28 |
| Cabbage | Start seeds indoors (spring) | Apr 1 – Apr 29 |
| Cabbage | Transplant outdoors (spring) | Apr 29 – May 30 |
| Cabbage | Start seeds indoors (fall) | May 8 – Jun 7 |
| Cabbage | Transplant outdoors (fall) | Jun 7 – Jul 8 |
| Leaf lettuce | Sow outdoors (spring) | Apr 29 – Jul 15 |
| Leaf lettuce | Sow outdoors (fall) | Jun 7 – Jul 24 |
| Spinach | Sow outdoors (spring) | Apr 22 – Jun 5 |
| Spinach | Sow outdoors (fall) | Jun 24 – Jul 29 |
| Radishes | Sow outdoors (spring) | Apr 29 – Jun 19 |
| Radishes | Sow outdoors (fall) | Jun 7 – Aug 8 |
| Kale | Sow outdoors (spring) | May 16 – Jun 5 |
| Kale | Sow outdoors (fall) | May 31 – Jul 8 |
| Carrots | Sow outdoors (spring) | May 30 – Jul 15 |
| Carrots | Sow outdoors (fall) | May 8 – Jun 23 |
| Garlic | Plant outdoors (fall) | Sep 7 – Oct 8 |
Where these dates come from
ZIP code 80517 is matched to the NOAA station Estes Park 3 Sse, CO, 1.9 km away, at 7,812 ft elevation (262 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Estes Park 3 Sse, CO (used) | 7,812 ft | May 30 | Sep 17 |
| Allenspark 3Nw, CO | 8,500 ft | Jun 14 | Sep 12 |
| Hourglass Rsvr, CO | 9,520 ft | — | — |
| Waterdale, CO | 5,230 ft | May 12 | Oct 1 |
Frost dates near Estes Park
- Glen Haven, CO 80532 · last May 30, first Sep 17
- Drake, CO 80515 · last May 30, first Sep 17
- Allenspark, CO 80510 · last Jun 14, first Sep 12
- Lyons, CO 80540 · last May 6, first Oct 5
- Masonville, CO 80541 · last May 12, first Oct 1
- Estes Park, CO 80511 · last —, first —
- Jamestown, CO 80455 · last May 24, first Sep 23
- Boulder, CO 80306 · last May 24, first Sep 23
Frequently asked questions
- When is the last frost in Estes Park, CO?
- For ZIP code 80517, the average last spring frost (32°F) is May 30, based on NOAA 1991-2020 climate normals for the Estes Park 3 Sse, CO weather station. There is a 1-in-10 chance of a frost after June 14.
- When is the first frost in Estes Park, CO?
- The average first fall frost (32°F) is September 17. There is a 1-in-10 chance of frost by September 3, so tender plants are at risk from that point on.
- How long is the growing season in 80517?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 109 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.