Frost Dates for St. Peters, MO
In St. Peters, MO, the average last spring frost is around Apr 9 and the average first fall frost around Oct 26, for a growing season of about 198 days. For frost-tender plants, wait until Apr 25, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the St Peters 2 Se, MO weather station, 1 mile away, elevation 575 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 25 | Oct 14 |
| 20% | Apr 21 | Oct 18 |
| 30% | Apr 17 | Oct 21 |
| 40% | Apr 13 | Oct 24 |
| 50% | Apr 9 | Oct 26 |
| 60% | Apr 6 | Oct 28 |
| 70% | Apr 3 | Oct 31 |
| 80% | Mar 31 | Nov 3 |
| 90% | Mar 27 | Nov 7 |
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 23 | Oct 17 |
| Frost / freeze (32°F) | Apr 9 | Oct 26 |
| Hard freeze (28°F) | Mar 31 | Nov 5 |
Planting calendar for St. Peters
Transplant Apr 16 – Apr 30
Transplant Apr 23 – May 7
Transplant Apr 23 – May 7
Transplant Apr 16 – Apr 30
Sow or transplant Apr 16 – Apr 30
Sow or transplant Apr 16 – Apr 30
Sow or transplant Apr 23 – May 7
Sow or transplant Mar 12 – Mar 26
Fall sowing Aug 31 – Sep 28
Fall sowing Aug 31 – Sep 21
Fall sowing Aug 17 – Aug 31
Sow or transplant Mar 12 – Mar 26
Fall sowing Aug 17 – Sep 14
Transplant Mar 26 – Apr 9
Fall sowing Aug 3 – Aug 17
Transplant Mar 19 – Apr 2
Fall sowing Aug 3 – Aug 17
Fall sowing Aug 3 – Aug 17
Fall sowing Sep 14 – Oct 5
Fall sowing Aug 17 – Aug 31
Plant Mar 12 – Mar 26
Based on the average last frost (Apr 9) and first frost (Oct 26). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.