Frost Dates for North Chicago, IL
In North Chicago, IL, the average last spring frost is around Apr 30 and the average first fall frost around Oct 19, for a growing season of about 170 days. For frost-tender plants, wait until May 14, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Waukegan, IL weather station, 3 miles away, elevation 700 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 14 | Sep 30 |
| 20% | May 7 | Oct 7 |
| 30% | May 4 | Oct 12 |
| 40% | May 2 | Oct 16 |
| 50% | Apr 30 | Oct 19 |
| 60% | Apr 27 | Oct 23 |
| 70% | Apr 23 | Oct 26 |
| 80% | Apr 20 | Oct 29 |
| 90% | Apr 15 | Nov 3 |
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 8 | Oct 8 |
| Frost / freeze (32°F) | Apr 30 | Oct 19 |
| Hard freeze (28°F) | Apr 20 | Oct 30 |
Planting calendar for North Chicago
Transplant May 7 – May 21
Transplant May 14 – May 28
Transplant May 14 – May 28
Transplant May 7 – May 21
Sow or transplant May 7 – May 21
Sow or transplant May 7 – May 21
Sow or transplant May 14 – May 28
Sow or transplant Apr 2 – Apr 16
Fall sowing Aug 24 – Sep 21
Fall sowing Aug 24 – Sep 14
Fall sowing Aug 10 – Aug 24
Sow or transplant Apr 2 – Apr 16
Fall sowing Aug 10 – Sep 7
Transplant Apr 16 – Apr 30
Fall sowing Jul 27 – Aug 10
Transplant Apr 9 – Apr 23
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 Apr 2 – Apr 16
Based on the average last frost (Apr 30) and first frost (Oct 19). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.