Frost Dates for Maryland Heights, MO
In Maryland Heights, MO, the average last spring frost is around Apr 4 and the average first fall frost around Oct 29, for a growing season of about 206 days. For frost-tender plants, wait until Apr 21, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the St Charles 7 Ssw, MO weather station, 4 miles away, elevation 450 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 21 | Oct 15 |
| 20% | Apr 14 | Oct 20 |
| 30% | Apr 10 | Oct 24 |
| 40% | Apr 7 | Oct 27 |
| 50% | Apr 4 | Oct 29 |
| 60% | Apr 2 | Oct 31 |
| 70% | Mar 31 | Nov 2 |
| 80% | Mar 27 | Nov 6 |
| 90% | Mar 20 | Nov 11 |
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 16 | Oct 19 |
| Frost / freeze (32°F) | Apr 4 | Oct 29 |
| Hard freeze (28°F) | Mar 25 | Nov 8 |
Planting calendar for Maryland Heights
Transplant Apr 11 – Apr 25
Transplant Apr 18 – May 2
Transplant Apr 18 – May 2
Transplant Apr 11 – Apr 25
Sow or transplant Apr 11 – Apr 25
Sow or transplant Apr 11 – Apr 25
Sow or transplant Apr 18 – May 2
Sow or transplant Mar 7 – Mar 21
Fall sowing Sep 3 – Oct 1
Fall sowing Sep 3 – Sep 24
Fall sowing Aug 20 – Sep 3
Sow or transplant Mar 7 – Mar 21
Fall sowing Aug 20 – Sep 17
Transplant Mar 21 – Apr 4
Fall sowing Aug 6 – Aug 20
Transplant Mar 14 – Mar 28
Fall sowing Aug 6 – Aug 20
Fall sowing Aug 6 – Aug 20
Fall sowing Sep 17 – Oct 8
Fall sowing Aug 20 – Sep 3
Plant Mar 7 – Mar 21
Based on the average last frost (Apr 4) and first frost (Oct 29). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.