Frost Dates for Quincy, IL
In Quincy, IL, the average last spring frost is around Apr 8 and the average first fall frost around Oct 30, for a growing season of about 204 days. For frost-tender plants, wait until Apr 23, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Quincy Dam 21, IL weather station, 3 miles away, elevation 483 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 23 | Oct 17 |
| 20% | Apr 18 | Oct 21 |
| 30% | Apr 15 | Oct 25 |
| 40% | Apr 11 | Oct 27 |
| 50% | Apr 8 | Oct 30 |
| 60% | Apr 5 | Nov 1 |
| 70% | Apr 3 | Nov 3 |
| 80% | Mar 31 | Nov 5 |
| 90% | Mar 24 | Nov 10 |
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 19 | Oct 20 |
| Frost / freeze (32°F) | Apr 8 | Oct 30 |
| Hard freeze (28°F) | Mar 30 | Nov 8 |
Planting calendar for Quincy
Transplant Apr 15 – Apr 29
Transplant Apr 22 – May 6
Transplant Apr 22 – May 6
Transplant Apr 15 – Apr 29
Sow or transplant Apr 15 – Apr 29
Sow or transplant Apr 15 – Apr 29
Sow or transplant Apr 22 – May 6
Sow or transplant Mar 11 – Mar 25
Fall sowing Sep 4 – Oct 2
Fall sowing Sep 4 – Sep 25
Fall sowing Aug 21 – Sep 4
Sow or transplant Mar 11 – Mar 25
Fall sowing Aug 21 – Sep 18
Transplant Mar 25 – Apr 8
Fall sowing Aug 7 – Aug 21
Transplant Mar 18 – Apr 1
Fall sowing Aug 7 – Aug 21
Fall sowing Aug 7 – Aug 21
Fall sowing Sep 18 – Oct 9
Fall sowing Aug 21 – Sep 4
Plant Mar 11 – Mar 25
Based on the average last frost (Apr 8) and first frost (Oct 30). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.