Frost Dates for Commerce City, CO
In Commerce City, CO, the average last spring frost is around May 3 and the average first fall frost around Oct 7, for a growing season of about 155 days. For frost-tender plants, wait until May 16, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Brighton 3 Se, CO weather station, 5 miles away, elevation 5,016 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.
Frost probability by date
Chance of a 32°F frost after the spring date, or before the fall date.
| Chance | Last spring frost | First fall frost |
|---|---|---|
| 10% | May 16 | Sep 26 |
| 20% | May 12 | Sep 30 |
| 30% | May 8 | Oct 2 |
| 40% | May 6 | Oct 5 |
| 50% | May 3 | Oct 7 |
| 60% | May 1 | Oct 10 |
| 70% | Apr 30 | Oct 13 |
| 80% | Apr 27 | Oct 16 |
| 90% | Apr 22 | Oct 19 |
Light frost vs. hard freeze
Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.
| Temperature | Last in spring | First in fall |
|---|---|---|
| Light frost (36°F) | May 13 | Sep 30 |
| Frost / freeze (32°F) | May 3 | Oct 7 |
| Hard freeze (28°F) | Apr 23 | Oct 16 |
Planting calendar for Commerce City
Transplant May 10 – May 24
Transplant May 17 – May 31
Transplant May 17 – May 31
Transplant May 10 – May 24
Sow or transplant May 10 – May 24
Sow or transplant May 10 – May 24
Sow or transplant May 17 – May 31
Sow or transplant Apr 5 – Apr 19
Fall sowing Aug 12 – Sep 9
Fall sowing Aug 12 – Sep 2
Fall sowing Jul 29 – Aug 12
Sow or transplant Apr 5 – Apr 19
Fall sowing Jul 29 – Aug 26
Transplant Apr 19 – May 3
Fall sowing Jul 15 – Jul 29
Transplant Apr 12 – Apr 26
Fall sowing Jul 15 – Jul 29
Fall sowing Jul 15 – Jul 29
Fall sowing Aug 26 – Sep 16
Fall sowing Jul 29 – Aug 12
Plant Apr 5 – Apr 19
Based on the average last frost (May 3) and first frost (Oct 7). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.