Frost dates for 80807Burlington, CO
The average last spring frost in Burlington is May 6 and the average first fall frost is October 9, giving a typical growing season of about 155 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 6
- Average first fall frost
- Oct 9
- Growing season
- 155 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 191 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 4 · May 15 · May 27 | Sep 19 · Oct 1 · Oct 12 | 139 days | 100% |
| Frost / freeze (32°F) | Apr 23 · May 6 · May 19 | Sep 27 · Oct 9 · Oct 20 | 155 days | 100% |
| Hard freeze (28°F) | Apr 13 · Apr 27 · May 9 | Oct 4 · Oct 18 · Oct 29 | 173 days | 100% |
Planting calendar for Burlington
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 5 – Jun 11 |
| Tomatoes | Transplant outdoors | May 22 – Jun 19 |
| Peppers | Start seeds indoors | Apr 5 – May 6 |
| Peppers | Transplant outdoors | Jun 5 – Jul 6 |
| Eggplant | Start seeds indoors | Apr 22 – May 21 |
| Eggplant | Transplant outdoors | Jun 5 – Jul 6 |
| Cucumbers | Sow outdoors | Jun 5 – Jun 29 |
| Summer squash | Sow outdoors | May 22 – Jul 6 |
| Winter squash & pumpkins | Sow outdoors | Jun 5 – Jul 6 |
| Snap beans | Sow outdoors | May 22 – Jul 22 |
| Sweet corn | Sow outdoors | May 22 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 5 – Jul 6 |
| Okra | Sow outdoors | May 29 – Jun 21 |
| Peas | Sow outdoors (spring) | Apr 5 – May 21 |
| Potatoes | Plant outdoors (spring) | Apr 5 – Jun 5 |
| Onions | Start seeds indoors (spring) | Feb 22 – Mar 21 |
| Onions | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (spring) | Mar 18 – Apr 21 |
| Broccoli | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 8 – Apr 5 |
| Cabbage | Transplant outdoors (spring) | Apr 5 – May 6 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Apr 5 – Jun 21 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 29 – May 12 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Apr 5 – May 26 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 22 – May 12 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 6 – Jun 21 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 80807 is matched to the NOAA station Burlington, CO, 0.5 km away, at 4,162 ft elevation (5 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Burlington, CO (used) | 4,162 ft | May 6 | Oct 9 |
| Burlington Carson Ap, CO | 4,192 ft | May 2 | Oct 10 |
| Stratton, CO | 4,399 ft | May 6 | Oct 9 |
| Arapahoe 14N, CO | 4,142 ft | May 9 | Oct 7 |
Frost dates near Burlington
- Bethune, CO 80805 · last May 6, first Oct 9
- Kanorado, KS 67741 · last May 2, first Oct 11
- Stratton, CO 80836 · last May 6, first Oct 9
- Kirk, CO 80824 · last May 4, first Oct 9
- Vona, CO 80861 · last May 6, first Oct 9
- Goodland, KS 67735 · last May 2, first Oct 11
- Saint Francis, KS 67756 · last Apr 30, first Oct 10
- Arapahoe, CO 80802 · last May 5, first Oct 9
Frequently asked questions
- When is the last frost in Burlington, CO?
- For ZIP code 80807, the average last spring frost (32°F) is May 6, based on NOAA 1991-2020 climate normals for the Burlington, CO weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Burlington, CO?
- The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 27, so tender plants are at risk from that point on.
- How long is the growing season in 80807?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 155 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.