Frost Dates for Des Moines, IA
In Des Moines, IA, the average last spring frost is around Apr 18 and the average first fall frost around Oct 20, for a growing season of about 184 days. For frost-tender plants, wait until May 2, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Des Moines Intl. Airport, IA weather station, 3 miles away, elevation 957 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 2 | Oct 4 |
| 20% | Apr 28 | Oct 10 |
| 30% | Apr 24 | Oct 14 |
| 40% | Apr 21 | Oct 17 |
| 50% | Apr 18 | Oct 20 |
| 60% | Apr 14 | Oct 23 |
| 70% | Apr 12 | Oct 25 |
| 80% | Apr 9 | Oct 28 |
| 90% | Apr 4 | Nov 1 |
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) | Apr 29 | Oct 9 |
| Frost / freeze (32°F) | Apr 18 | Oct 20 |
| Hard freeze (28°F) | Apr 8 | Oct 30 |
Planting calendar for Des Moines
Transplant Apr 25 – May 9
Transplant May 2 – May 16
Transplant May 2 – May 16
Transplant Apr 25 – May 9
Sow or transplant Apr 25 – May 9
Sow or transplant Apr 25 – May 9
Sow or transplant May 2 – May 16
Sow or transplant Mar 21 – Apr 4
Fall sowing Aug 25 – Sep 22
Fall sowing Aug 25 – Sep 15
Fall sowing Aug 11 – Aug 25
Sow or transplant Mar 21 – Apr 4
Fall sowing Aug 11 – Sep 8
Transplant Apr 4 – Apr 18
Fall sowing Jul 28 – Aug 11
Transplant Mar 28 – Apr 11
Fall sowing Jul 28 – Aug 11
Fall sowing Jul 28 – Aug 11
Fall sowing Sep 8 – Sep 29
Fall sowing Aug 11 – Aug 25
Plant Mar 21 – Apr 4
Based on the average last frost (Apr 18) and first frost (Oct 20). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.