In St. Louis, MO, the average last spring frost is Apr 12 and the average first fall frost is Oct 23, which leaves about 193 frost-free days for the garden. These dates come from NOAA climate normals for the St Louis Sprt Of S L Airport, MO weather station, at 462 feet above sea level.
A long season lets you do more than one planting: a spring crop, a second planting of quick crops in summer, and a fall garden. Succession planting works well here. Frost timing varies from year to year: in about 1 spring in 10 the last frost falls as late as Apr 27, and in about 1 fall in 10 the first frost arrives as early as Oct 11.
Frost dates for St. Louis, MO
| Chance of a freeze (32°F) after or before this date | Last spring frost | First fall frost | Freeze-free season |
|---|---|---|---|
| Optimistic (about 1 year in 10) | Mar 28 | Nov 5 | 222 days |
| Average (half of years) | Apr 12 | Oct 23 | 193 days |
| Cautious (9 years in 10 are safe) | Apr 27 | Oct 11 | 167 days |
Source: NOAA NCEI U.S. Climate Normals, 1991 to 2020. Use the cautious dates for tender crops such as tomatoes and peppers.
When to plant in St. Louis, MO
These windows count weeks forward and back from the average frost dates above. They are planning guides: check the forecast before planting tender crops, and see our what to plant now tool for today's date.
| Crop | Start seeds indoors | Plant outdoors in spring | Plant in fall |
|---|---|---|---|
| Tomatoes | Feb 15 to Mar 1 | Apr 19 to Apr 26 | – |
| Peppers | Feb 1 to Feb 15 | Apr 26 to May 3 | – |
| Eggplant | Feb 1 to Feb 15 | Apr 26 to May 3 | – |
| Onions | Feb 1 to Feb 15 | Mar 15 to Mar 29 | – |
| Parsley | Feb 1 to Feb 15 | Apr 12 to Apr 19 | – |
| Broccoli, cabbage, cauliflower | Feb 15 to Mar 1 | Mar 29 to Apr 5 | Jul 31 to Aug 28 |
| Basil | Mar 1 to Mar 1 | Apr 19 to Apr 26 | – |
| Peas | Sow outdoors | Mar 1 to Mar 15 | Jul 31 to Aug 28 |
| Spinach | Sow outdoors | Mar 1 to Mar 15 | Aug 28 to Sep 25 |
| Radishes | Sow outdoors | Mar 1 to Mar 15 | Aug 28 to Sep 25 |
| Lettuce | Sow outdoors | Mar 15 to Mar 29 | Aug 28 to Sep 25 |
| Carrots | Sow outdoors | Mar 15 to Mar 29 | Jul 31 to Aug 28 |
| Beets | Sow outdoors | Mar 15 to Mar 29 | Jul 31 to Aug 28 |
| Potatoes | Sow outdoors | Mar 15 to Mar 29 | – |
| Kale | Sow outdoors | Mar 15 to Mar 29 | Jul 31 to Aug 28 |
| Swiss chard | Sow outdoors | Mar 29 to Apr 12 | – |
| Cilantro | Sow outdoors | Mar 29 to Apr 12 | Aug 28 to Sep 25 |
| Dill | Sow outdoors | Apr 12 to Apr 19 | – |
| Bush beans | Sow outdoors | Apr 19 to Apr 26 | Jul 20 to Aug 3 |
| Pole beans | Sow outdoors | Apr 19 to Apr 26 | – |
| Sweet corn | Sow outdoors | Apr 19 to Apr 26 | – |
| Cucumbers | Sow outdoors | Apr 19 to Apr 26 | Jul 10 to Jul 24 |
| Zucchini and summer squash | Sow outdoors | Apr 19 to Apr 26 | Jul 20 to Aug 3 |
| Winter squash | Sow outdoors | Apr 19 to Apr 26 | – |
| Sweet potatoes (slips) | Sow outdoors | Apr 26 to May 10 | – |
| Okra | Sow outdoors | Apr 26 to May 10 | – |
A dash in the fall column means the crop is not usually planted in fall, or the season is too short.
Overnight lows this week
The National Weather Service forecast shows frost risk on: Sun 15 night (24°F), Mon 16 night (27°F), Tue 17 night (31°F). Cover tender plants before dark on those nights.
| Night | Forecast low | Frost risk |
|---|---|---|
| Sun 15 night | 24°F | Freeze |
| Mon 16 night | 27°F | Freeze |
| Tue 17 night | 31°F | Freeze |
| Wed 18 night | 42°F | No frost expected |
| Thu 19 night | 44°F | No frost expected |
| Fri 20 night | 47°F | No frost expected |
| Sat 21 night | 40°F | No frost expected |
Live forecast for the station location, from the National Weather Service. For your own ZIP code, use our garden weather forecast.
More garden tools for St. Louis, MO
- Frost dates by ZIP code for your exact location
- What to plant now, based on today's date
- Garden weather forecast by ZIP code
- Safe transplant date calculator
Frequently asked questions
When is the last frost in St. Louis, MO?
The average last spring frost is Apr 12. A late frost as far out as Apr 27 happens in about 1 year in 10, so tender plants such as tomatoes and peppers are safest after that cautious date.
When is the first frost in St. Louis, MO?
The average first fall frost is Oct 23. It can arrive as early as Oct 11 in about 1 year in 10, so plan to harvest tender crops before then.
How long is the growing season in St. Louis, MO?
The average freeze-free season is about 193 days, between the average last spring frost and the average first fall frost.
Where do these dates come from?
They come from the NOAA 1991 to 2020 U.S. Climate Normals for the St Louis Sprt Of S L Airport, MO station. Hills, valleys, lakes and city heat can shift frost by a week or more, so compare with neighbors who garden near you.