Frost dates for 63052Imperial, MO
The average last spring frost in Imperial is April 9 and the average first fall frost is October 26, giving a typical growing season of about 197 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 9
- Average first fall frost
- Oct 26
- Growing season
- 197 days
Safer after Apr 25 (1-in-10 risk)
Possible by Oct 14 (1-in-10 risk)
Last frost typically in 160 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 5 · Apr 22 · May 8 | Oct 4 · Oct 17 · Oct 28 | 174 days | 100% |
| Frost / freeze (32°F) | Mar 25 · Apr 9 · Apr 25 | Oct 14 · Oct 26 · Nov 8 | 197 days | 100% |
| Hard freeze (28°F) | Mar 12 · Mar 31 · Apr 15 | Oct 23 · Nov 5 · Nov 23 | 221 days | 100% |
Planting calendar for Imperial
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 9 – May 15 |
| Tomatoes | Transplant outdoors | Apr 25 – Jul 6 |
| Peppers | Start seeds indoors | Mar 9 – Apr 9 |
| Peppers | Transplant outdoors | May 9 – Jun 9 |
| Eggplant | Start seeds indoors | Mar 26 – Apr 24 |
| Eggplant | Transplant outdoors | May 9 – Jun 9 |
| Cucumbers | Sow outdoors | May 9 – Jul 16 |
| Summer squash | Sow outdoors | Apr 25 – Jun 9 |
| Winter squash & pumpkins | Sow outdoors | May 9 – Jun 9 |
| Snap beans | Sow outdoors | Apr 25 – Aug 8 |
| Sweet corn | Sow outdoors | Apr 25 – Jul 6 |
| Watermelon & cantaloupe | Sow outdoors | May 9 – Jun 9 |
| Okra | Sow outdoors | May 2 – May 25 |
| Peas | Sow outdoors (spring) | Mar 9 – Apr 24 |
| Potatoes | Plant outdoors (spring) | Mar 9 – May 9 |
| Onions | Start seeds indoors (spring) | Jan 26 – Feb 22 |
| Onions | Transplant outdoors (spring) | Mar 26 – Apr 24 |
| Broccoli | Start seeds indoors (spring) | Feb 19 – Mar 25 |
| Broccoli | Transplant outdoors (spring) | Mar 26 – Apr 24 |
| Broccoli | Start seeds indoors (fall) | Jun 26 – Jul 6 |
| Broccoli | Transplant outdoors (fall) | Jul 26 – Aug 6 |
| Cabbage | Start seeds indoors (spring) | Feb 9 – Mar 9 |
| Cabbage | Transplant outdoors (spring) | Mar 9 – Apr 9 |
| Cabbage | Start seeds indoors (fall) | Jun 16 – Jul 16 |
| Cabbage | Transplant outdoors (fall) | Jul 16 – Aug 16 |
| Leaf lettuce | Sow outdoors (spring) | Mar 9 – May 25 |
| Leaf lettuce | Sow outdoors (fall) | Jul 16 – Sep 1 |
| Spinach | Sow outdoors (spring) | Mar 2 – Apr 15 |
| Spinach | Sow outdoors (fall) | Aug 2 – Sep 6 |
| Radishes | Sow outdoors (spring) | Mar 9 – Apr 29 |
| Radishes | Sow outdoors (fall) | Jul 16 – Sep 16 |
| Kale | Sow outdoors (spring) | Mar 26 – Apr 15 |
| Kale | Sow outdoors (fall) | Jul 9 – Aug 16 |
| Carrots | Sow outdoors (spring) | Apr 9 – May 25 |
| Carrots | Sow outdoors (fall) | Jun 16 – Aug 1 |
| Garlic | Plant outdoors (fall) | Oct 16 – Nov 16 |
Where these dates come from
ZIP code 63052 is matched to the NOAA station Festus, MO, 19.7 km away, at 600 ft elevation (27 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Festus, MO (used) | 600 ft | Apr 9 | Oct 26 |
| Cahokia, IL | 400 ft | Apr 6 | Oct 27 |
| St Louis Sci Ctr, MO | 515 ft | Apr 1 | Nov 4 |
| Cahokia St Louis Ap, IL | 413 ft | Apr 8 | Oct 26 |
Frost dates near Imperial
- Arnold, MO 63010 · last Apr 6, first Oct 27
- Liguori, MO 63057 · last Apr 9, first Oct 26
- Barnhart, MO 63012 · last Apr 9, first Oct 26
- Kimmswick, MO 63053 · last Apr 9, first Oct 26
- House Springs, MO 63051 · last Apr 9, first Oct 26
- High Ridge, MO 63049 · last Apr 10, first Oct 26
- Saint Louis, MO 63128 · last Apr 1, first Nov 4
- Fenton, MO 63026 · last Apr 1, first Nov 4
Frequently asked questions
- When is the last frost in Imperial, MO?
- For ZIP code 63052, the average last spring frost (32°F) is April 9, based on NOAA 1991-2020 climate normals for the Festus, MO weather station. There is a 1-in-10 chance of a frost after April 25.
- When is the first frost in Imperial, MO?
- The average first fall frost (32°F) is October 26. There is a 1-in-10 chance of frost by October 14, so tender plants are at risk from that point on.
- How long is the growing season in 63052?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 197 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.