Frost Dates for Erie, CO
In Erie, CO, the average last spring frost is around May 7 and the average first fall frost around Oct 5, for a growing season of about 151 days. For frost-tender plants, wait until May 22, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Longmont 2 Ese, CO weather station, 9 miles away, elevation 4,950 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 22 | Sep 23 |
| 20% | May 16 | Sep 27 |
| 30% | May 13 | Oct 1 |
| 40% | May 10 | Oct 2 |
| 50% | May 7 | Oct 5 |
| 60% | May 4 | Oct 6 |
| 70% | May 1 | Oct 9 |
| 80% | Apr 29 | Oct 12 |
| 90% | Apr 24 | Oct 16 |
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 18 | Sep 28 |
| Frost / freeze (32°F) | May 7 | Oct 5 |
| Hard freeze (28°F) | Apr 28 | Oct 12 |
Planting calendar for Erie
Transplant May 14 – May 28
Transplant May 21 – Jun 4
Transplant May 21 – Jun 4
Transplant May 14 – May 28
Sow or transplant May 14 – May 28
Sow or transplant May 14 – May 28
Sow or transplant May 21 – Jun 4
Sow or transplant Apr 9 – Apr 23
Fall sowing Aug 10 – Sep 7
Fall sowing Aug 10 – Aug 31
Fall sowing Jul 27 – Aug 10
Sow or transplant Apr 9 – Apr 23
Fall sowing Jul 27 – Aug 24
Transplant Apr 23 – May 7
Fall sowing Jul 13 – Jul 27
Transplant Apr 16 – Apr 30
Fall sowing Jul 13 – Jul 27
Fall sowing Jul 13 – Jul 27
Fall sowing Aug 24 – Sep 14
Fall sowing Jul 27 – Aug 10
Plant Apr 9 – Apr 23
Based on the average last frost (May 7) and first frost (Oct 5). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.