Frost Dates for Parker, CO
In Parker, CO, the average last spring frost is around May 9 and the average first fall frost around Oct 3, for a growing season of about 145 days. For frost-tender plants, wait until May 23, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Parker, CO weather station, 1 mile away, elevation 5,904 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 23 | Sep 21 |
| 20% | May 18 | Sep 25 |
| 30% | May 14 | Sep 28 |
| 40% | May 12 | Oct 1 |
| 50% | May 9 | Oct 3 |
| 60% | May 6 | Oct 5 |
| 70% | May 4 | Oct 7 |
| 80% | May 1 | Oct 11 |
| 90% | Apr 27 | Oct 15 |
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 20 | Sep 25 |
| Frost / freeze (32°F) | May 9 | Oct 3 |
| Hard freeze (28°F) | Apr 29 | Oct 12 |
Planting calendar for Parker
Transplant May 16 – May 30
Transplant May 23 – Jun 6
Transplant May 23 – Jun 6
Transplant May 16 – May 30
Sow or transplant May 16 – May 30
Sow or transplant May 16 – May 30
Sow or transplant May 23 – Jun 6
Sow or transplant Apr 11 – Apr 25
Fall sowing Aug 8 – Sep 5
Fall sowing Aug 8 – Aug 29
Fall sowing Jul 25 – Aug 8
Sow or transplant Apr 11 – Apr 25
Fall sowing Jul 25 – Aug 22
Transplant Apr 25 – May 9
Fall sowing Jul 11 – Jul 25
Transplant Apr 18 – May 2
Fall sowing Jul 11 – Jul 25
Fall sowing Jul 11 – Jul 25
Fall sowing Aug 22 – Sep 12
Fall sowing Jul 25 – Aug 8
Plant Apr 11 – Apr 25
Based on the average last frost (May 9) and first frost (Oct 3). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.