Frost dates for 63134Saint Louis, MO
The average last spring frost in Saint Louis is April 2 and the average first fall frost is November 4, giving a typical growing season of about 215 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 2
- Average first fall frost
- Nov 4
- Growing season
- 215 days
Safer after Apr 17 (1-in-10 risk)
Possible by Oct 23 (1-in-10 risk)
First frost typically in 2 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) | Mar 31 · Apr 13 · Apr 28 | Oct 14 · Oct 26 · Nov 6 | 195 days | 100% |
| Frost / freeze (32°F) | Mar 17 · Apr 2 · Apr 17 | Oct 23 · Nov 4 · Nov 18 | 215 days | 100% |
| Hard freeze (28°F) | Mar 5 · Mar 23 · Apr 7 | Nov 2 · Nov 13 · Nov 30 | 236 days | 100% |
Planting calendar for Saint Louis
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 2 – May 8 |
| Tomatoes | Transplant outdoors | Apr 18 – Jul 15 |
| Peppers | Start seeds indoors | Mar 2 – Apr 2 |
| Peppers | Transplant outdoors | May 2 – Jun 2 |
| Eggplant | Start seeds indoors | Mar 19 – Apr 17 |
| Eggplant | Transplant outdoors | May 2 – Jun 2 |
| Cucumbers | Sow outdoors | May 2 – Jul 25 |
| Summer squash | Sow outdoors | Apr 18 – Jun 2 |
| Winter squash & pumpkins | Sow outdoors | May 2 – Jun 2 |
| Snap beans | Sow outdoors | Apr 18 – Aug 17 |
| Sweet corn | Sow outdoors | Apr 18 – Jul 15 |
| Watermelon & cantaloupe | Sow outdoors | May 2 – Jun 2 |
| Okra | Sow outdoors | Apr 25 – May 18 |
| Peas | Sow outdoors (spring) | Mar 2 – Apr 17 |
| Potatoes | Plant outdoors (spring) | Mar 2 – May 2 |
| Onions | Start seeds indoors (spring) | Jan 19 – Feb 15 |
| Onions | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (spring) | Feb 12 – Mar 18 |
| Broccoli | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (fall) | Jul 5 – Jul 15 |
| Broccoli | Transplant outdoors (fall) | Aug 4 – Aug 15 |
| Cabbage | Start seeds indoors (spring) | Feb 2 – Mar 2 |
| Cabbage | Transplant outdoors (spring) | Mar 2 – Apr 2 |
| Cabbage | Start seeds indoors (fall) | Jun 25 – Jul 25 |
| Cabbage | Transplant outdoors (fall) | Jul 25 – Aug 25 |
| Leaf lettuce | Sow outdoors (spring) | Mar 2 – May 18 |
| Leaf lettuce | Sow outdoors (fall) | Jul 25 – Sep 10 |
| Spinach | Sow outdoors (spring) | Feb 23 – Apr 8 |
| Spinach | Sow outdoors (fall) | Aug 11 – Sep 15 |
| Radishes | Sow outdoors (spring) | Mar 2 – Apr 22 |
| Radishes | Sow outdoors (fall) | Jul 25 – Sep 25 |
| Kale | Sow outdoors (spring) | Mar 19 – Apr 8 |
| Kale | Sow outdoors (fall) | Jul 18 – Aug 25 |
| Carrots | Sow outdoors (spring) | Apr 2 – May 18 |
| Carrots | Sow outdoors (fall) | Jun 25 – Aug 10 |
| Garlic | Plant outdoors (fall) | Oct 25 – Nov 25 |
Where these dates come from
ZIP code 63134 is matched to the NOAA station St Louis Lambert Intl Ap, MO, 3 km away, at 531 ft elevation (83 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| St Louis Lambert Intl Ap, MO (used) | 531 ft | Apr 2 | Nov 4 |
| St Louis Sci Ctr, MO | 515 ft | Apr 1 | Nov 4 |
| St Charles Elm Pt, MO | 472 ft | Apr 8 | Oct 29 |
| St Charles 7 Ssw, MO | 450 ft | Apr 4 | Oct 29 |
Frost dates near Saint Louis
- Saint Louis, MO 63140 · last Apr 2, first Nov 4
- Saint Ann, MO 63074 · last Apr 2, first Nov 4
- Hazelwood, MO 63042 · last Apr 2, first Nov 4
- Bridgeton, MO 63044 · last Apr 2, first Nov 4
- Florissant, MO 63031 · last Apr 2, first Nov 4
- Maryland Heights, MO 63043 · last Apr 2, first Nov 4
- Earth City, MO 63045 · last Apr 8, first Oct 29
- Saint Charles, MO 63302 · last Apr 8, first Oct 29
Frequently asked questions
- When is the last frost in Saint Louis, MO?
- For ZIP code 63134, the average last spring frost (32°F) is April 2, based on NOAA 1991-2020 climate normals for the St Louis Lambert Intl Ap, MO weather station. There is a 1-in-10 chance of a frost after April 17.
- When is the first frost in Saint Louis, MO?
- The average first fall frost (32°F) is November 4. There is a 1-in-10 chance of frost by October 23, so tender plants are at risk from that point on.
- How long is the growing season in 63134?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 215 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.