Frost Dates for Champaign, IL
In Champaign, IL, the average last spring frost is around Apr 15 and the average first fall frost around Oct 24, for a growing season of about 190 days. For frost-tender plants, wait until Apr 29, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Champaign 3S, IL weather station, 3 miles away, elevation 721 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% | Apr 29 | Oct 11 |
| 20% | Apr 24 | Oct 16 |
| 30% | Apr 21 | Oct 19 |
| 40% | Apr 18 | Oct 22 |
| 50% | Apr 15 | Oct 24 |
| 60% | Apr 12 | Oct 26 |
| 70% | Apr 8 | Oct 29 |
| 80% | Apr 5 | Oct 31 |
| 90% | Apr 1 | Nov 5 |
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 26 | Oct 15 |
| Frost / freeze (32°F) | Apr 15 | Oct 24 |
| Hard freeze (28°F) | Apr 4 | Nov 2 |
Planting calendar for Champaign
Transplant Apr 22 – May 6
Transplant Apr 29 – May 13
Transplant Apr 29 – May 13
Transplant Apr 22 – May 6
Sow or transplant Apr 22 – May 6
Sow or transplant Apr 22 – May 6
Sow or transplant Apr 29 – May 13
Sow or transplant Mar 18 – Apr 1
Fall sowing Aug 29 – Sep 26
Fall sowing Aug 29 – Sep 19
Fall sowing Aug 15 – Aug 29
Sow or transplant Mar 18 – Apr 1
Fall sowing Aug 15 – Sep 12
Transplant Apr 1 – Apr 15
Fall sowing Aug 1 – Aug 15
Transplant Mar 25 – Apr 8
Fall sowing Aug 1 – Aug 15
Fall sowing Aug 1 – Aug 15
Fall sowing Sep 12 – Oct 3
Fall sowing Aug 15 – Aug 29
Plant Mar 18 – Apr 1
Based on the average last frost (Apr 15) and first frost (Oct 24). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.