Frost dates for 80013Aurora, CO
The average last spring frost in Aurora is May 7 and the average first fall frost is October 8, giving a typical growing season of about 152 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 7
- Average first fall frost
- Oct 8
- Growing season
- 152 days
Safer after May 21 (1-in-10 risk)
Possible by Sep 25 (1-in-10 risk)
Last frost typically in 187 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 7 · May 18 · Jun 1 | Sep 18 · Sep 30 · Oct 12 | 132 days | 100% |
| Frost / freeze (32°F) | Apr 26 · May 7 · May 21 | Sep 25 · Oct 8 · Oct 19 | 152 days | 100% |
| Hard freeze (28°F) | Apr 11 · Apr 29 · May 10 | Sep 30 · Oct 15 · Oct 27 | 169 days | 100% |
Planting calendar for Aurora
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 6 – Jun 12 |
| Tomatoes | Transplant outdoors | May 23 – Jun 18 |
| Peppers | Start seeds indoors | Apr 6 – May 7 |
| Peppers | Transplant outdoors | Jun 6 – Jul 7 |
| Eggplant | Start seeds indoors | Apr 23 – May 22 |
| Eggplant | Transplant outdoors | Jun 6 – Jul 7 |
| Cucumbers | Sow outdoors | Jun 6 – Jun 28 |
| Summer squash | Sow outdoors | May 23 – Jul 7 |
| Winter squash & pumpkins | Sow outdoors | Jun 6 – Jul 7 |
| Snap beans | Sow outdoors | May 23 – Jul 21 |
| Sweet corn | Sow outdoors | May 23 – Jun 18 |
| Watermelon & cantaloupe | Sow outdoors | Jun 6 – Jul 7 |
| Okra | Sow outdoors | May 30 – Jun 22 |
| Peas | Sow outdoors (spring) | Apr 6 – May 22 |
| Potatoes | Plant outdoors (spring) | Apr 6 – Jun 6 |
| Onions | Start seeds indoors (spring) | Feb 23 – Mar 22 |
| Onions | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (spring) | Mar 19 – Apr 22 |
| Broccoli | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (fall) | Jun 8 – Jun 18 |
| Broccoli | Transplant outdoors (fall) | Jul 8 – Jul 19 |
| Cabbage | Start seeds indoors (spring) | Mar 9 – Apr 6 |
| Cabbage | Transplant outdoors (spring) | Apr 6 – May 7 |
| Cabbage | Start seeds indoors (fall) | May 29 – Jun 28 |
| Cabbage | Transplant outdoors (fall) | Jun 28 – Jul 29 |
| Leaf lettuce | Sow outdoors (spring) | Apr 6 – Jun 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 28 – Aug 14 |
| Spinach | Sow outdoors (spring) | Mar 30 – May 13 |
| Spinach | Sow outdoors (fall) | Jul 15 – Aug 19 |
| Radishes | Sow outdoors (spring) | Apr 6 – May 27 |
| Radishes | Sow outdoors (fall) | Jun 28 – Aug 29 |
| Kale | Sow outdoors (spring) | Apr 23 – May 13 |
| Kale | Sow outdoors (fall) | Jun 21 – Jul 29 |
| Carrots | Sow outdoors (spring) | May 7 – Jun 22 |
| Carrots | Sow outdoors (fall) | May 29 – Jul 14 |
| Garlic | Plant outdoors (fall) | Sep 28 – Oct 29 |
Where these dates come from
ZIP code 80013 is matched to the NOAA station Cherry Creek Dam, CO, 5.3 km away, at 5,647 ft elevation (16 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cherry Creek Dam, CO (used) | 5,647 ft | May 7 | Oct 8 |
| Denver Centennial Ap, CO | 5,883 ft | May 5 | Oct 8 |
| Denver-Stapleton, CO | 5,286 ft | May 4 | Oct 8 |
| Parker, CO | 5,904 ft | May 9 | Oct 3 |
Frost dates near Aurora
- Aurora, CO 80015 · last May 5, first Oct 8
- Denver, CO 80231 · last May 4, first Oct 8
- Englewood, CO 80111 · last May 5, first Oct 8
- Lone Tree, CO 80124 · last May 5, first Oct 8
- Littleton, CO 80121 · last May 2, first Oct 11
- Parker, CO 80138 · last May 9, first Oct 3
- Watkins, CO 80137 · last May 5, first Oct 9
- Commerce City, CO 80037 · last May 4, first Oct 8
Frequently asked questions
- When is the last frost in Aurora, CO?
- For ZIP code 80013, the average last spring frost (32°F) is May 7, based on NOAA 1991-2020 climate normals for the Cherry Creek Dam, CO weather station. There is a 1-in-10 chance of a frost after May 21.
- When is the first frost in Aurora, CO?
- The average first fall frost (32°F) is October 8. There is a 1-in-10 chance of frost by September 25, so tender plants are at risk from that point on.
- How long is the growing season in 80013?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 152 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.