Frost Dates for West Chicago, IL
In West Chicago, IL, the average last spring frost is around Apr 25 and the average first fall frost around Oct 19, for a growing season of about 174 days. For frost-tender plants, wait until May 12, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the West Chicago Dupage Airport, IL weather station, 2 miles away, elevation 754 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 12 | Oct 5 |
| 20% | May 5 | Oct 10 |
| 30% | May 1 | Oct 14 |
| 40% | Apr 28 | Oct 16 |
| 50% | Apr 25 | Oct 19 |
| 60% | Apr 23 | Oct 21 |
| 70% | Apr 19 | Oct 24 |
| 80% | Apr 16 | Oct 26 |
| 90% | Apr 11 | Oct 30 |
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 6 | Oct 7 |
| Frost / freeze (32°F) | Apr 25 | Oct 19 |
| Hard freeze (28°F) | Apr 14 | Oct 29 |
Planting calendar for West Chicago
Transplant May 2 – May 16
Transplant May 9 – May 23
Transplant May 9 – May 23
Transplant May 2 – May 16
Sow or transplant May 2 – May 16
Sow or transplant May 2 – May 16
Sow or transplant May 9 – May 23
Sow or transplant Mar 28 – Apr 11
Fall sowing Aug 24 – Sep 21
Fall sowing Aug 24 – Sep 14
Fall sowing Aug 10 – Aug 24
Sow or transplant Mar 28 – Apr 11
Fall sowing Aug 10 – Sep 7
Transplant Apr 11 – Apr 25
Fall sowing Jul 27 – Aug 10
Transplant Apr 4 – Apr 18
Fall sowing Jul 27 – Aug 10
Fall sowing Jul 27 – Aug 10
Fall sowing Sep 7 – Sep 28
Fall sowing Aug 10 – Aug 24
Plant Mar 28 – Apr 11
Based on the average last frost (Apr 25) and first frost (Oct 19). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.