Frost Dates for Zionsville, IN
In Zionsville, IN, the average last spring frost is around Apr 21 and the average first fall frost around Oct 20, for a growing season of about 180 days. For frost-tender plants, wait until May 6, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Whitestown, IN weather station, 2 miles away, elevation 941 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 6 | Oct 5 |
| 20% | May 1 | Oct 10 |
| 30% | Apr 27 | Oct 14 |
| 40% | Apr 24 | Oct 17 |
| 50% | Apr 21 | Oct 20 |
| 60% | Apr 18 | Oct 22 |
| 70% | Apr 16 | Oct 25 |
| 80% | Apr 12 | Oct 28 |
| 90% | Apr 6 | 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) | May 1 | Oct 8 |
| Frost / freeze (32°F) | Apr 21 | Oct 20 |
| Hard freeze (28°F) | Apr 9 | Oct 31 |
Planting calendar for Zionsville
Transplant Apr 28 – May 12
Transplant May 5 – May 19
Transplant May 5 – May 19
Transplant Apr 28 – May 12
Sow or transplant Apr 28 – May 12
Sow or transplant Apr 28 – May 12
Sow or transplant May 5 – May 19
Sow or transplant Mar 24 – Apr 7
Fall sowing Aug 25 – Sep 22
Fall sowing Aug 25 – Sep 15
Fall sowing Aug 11 – Aug 25
Sow or transplant Mar 24 – Apr 7
Fall sowing Aug 11 – Sep 8
Transplant Apr 7 – Apr 21
Fall sowing Jul 28 – Aug 11
Transplant Mar 31 – Apr 14
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 24 – Apr 7
Based on the average last frost (Apr 21) and first frost (Oct 20). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.