Frost dates for 80015Aurora, CO
The average last spring frost in Aurora is May 5 and the average first fall frost is October 8, giving a typical growing season of about 154 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 5
- Average first fall frost
- Oct 8
- Growing season
- 154 days
Safer after May 17 (1-in-10 risk)
Possible by Sep 25 (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 3 · May 15 · May 30 | Sep 17 · Oct 1 · Oct 12 | 136 days | 100% |
| Frost / freeze (32°F) | Apr 24 · May 5 · May 17 | Sep 25 · Oct 8 · Oct 20 | 154 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 25 · May 9 | Oct 4 · Oct 17 · Oct 28 | 172 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 4 – Jun 10 |
| Tomatoes | Transplant outdoors | May 21 – Jun 18 |
| Peppers | Start seeds indoors | Apr 4 – May 5 |
| Peppers | Transplant outdoors | Jun 4 – Jul 5 |
| Eggplant | Start seeds indoors | Apr 21 – May 20 |
| Eggplant | Transplant outdoors | Jun 4 – Jul 5 |
| Cucumbers | Sow outdoors | Jun 4 – Jun 28 |
| Summer squash | Sow outdoors | May 21 – Jul 5 |
| Winter squash & pumpkins | Sow outdoors | Jun 4 – Jul 5 |
| Snap beans | Sow outdoors | May 21 – Jul 21 |
| Sweet corn | Sow outdoors | May 21 – Jun 18 |
| Watermelon & cantaloupe | Sow outdoors | Jun 4 – Jul 5 |
| Okra | Sow outdoors | May 28 – Jun 20 |
| Peas | Sow outdoors (spring) | Apr 4 – May 20 |
| Potatoes | Plant outdoors (spring) | Apr 4 – Jun 4 |
| Onions | Start seeds indoors (spring) | Feb 21 – Mar 20 |
| Onions | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (spring) | Mar 17 – Apr 20 |
| Broccoli | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (fall) | Jun 8 – Jun 18 |
| Broccoli | Transplant outdoors (fall) | Jul 8 – Jul 19 |
| Cabbage | Start seeds indoors (spring) | Mar 7 – Apr 4 |
| Cabbage | Transplant outdoors (spring) | Apr 4 – May 5 |
| Cabbage | Start seeds indoors (fall) | May 29 – Jun 28 |
| Cabbage | Transplant outdoors (fall) | Jun 28 – Jul 29 |
| Leaf lettuce | Sow outdoors (spring) | Apr 4 – Jun 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 28 – Aug 14 |
| Spinach | Sow outdoors (spring) | Mar 28 – May 11 |
| Spinach | Sow outdoors (fall) | Jul 15 – Aug 19 |
| Radishes | Sow outdoors (spring) | Apr 4 – May 25 |
| Radishes | Sow outdoors (fall) | Jun 28 – Aug 29 |
| Kale | Sow outdoors (spring) | Apr 21 – May 11 |
| Kale | Sow outdoors (fall) | Jun 21 – Jul 29 |
| Carrots | Sow outdoors (spring) | May 5 – Jun 20 |
| Carrots | Sow outdoors (fall) | May 29 – Jul 14 |
| Garlic | Plant outdoors (fall) | Sep 28 – Oct 29 |
Where these dates come from
ZIP code 80015 is matched to the NOAA station Denver Centennial Ap, CO, 8.1 km away, at 5,883 ft elevation (73 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Denver Centennial Ap, CO (used) | 5,883 ft | May 5 | Oct 8 |
| Cherry Creek Dam, CO | 5,647 ft | May 7 | Oct 8 |
| Parker, CO | 5,904 ft | May 9 | Oct 3 |
| Denver-Stapleton, CO | 5,286 ft | May 4 | Oct 8 |
Frost dates near Aurora
- Aurora, CO 80013 · last May 7, first Oct 8
- Englewood, CO 80111 · last May 5, first Oct 8
- Denver, CO 80237 · last May 2, first Oct 11
- Lone Tree, CO 80124 · last May 5, first Oct 8
- Parker, CO 80138 · last May 9, first Oct 3
- Littleton, CO 80121 · last May 2, first Oct 11
- Castle Rock, CO 80108 · last May 9, first Oct 2
- Watkins, CO 80137 · last May 5, first Oct 9
Frequently asked questions
- When is the last frost in Aurora, CO?
- For ZIP code 80015, the average last spring frost (32°F) is May 5, based on NOAA 1991-2020 climate normals for the Denver Centennial Ap, CO weather station. There is a 1-in-10 chance of a frost after May 17.
- 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 80015?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 154 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.