Columbia, Missouri: planting zone & frost dates
Columbia is in USDA plant hardiness zone 6b, where the average coldest winter night reaches -5 to 0°F (-20.6 to -17.8°C). The typical last spring frost is around Apr 12 and the first fall frost around Oct 25.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Apr 21 | Oct 17 |
| Typical planning date (30% risk) | Apr 12 | Oct 25 |
| Median (50%) | Apr 5 | Oct 31 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station COLUMBIA U OF M, MO (USC00231801), 0.4 mi (0.7 km) from the city center and 3 ft higher than the city center (+1 m). Record used for the 1991–2020 normals: 24 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Columbia
All 4 ZIP codes covering Columbia are in zone 6b.
Vegetable planting calendar for Columbia
Dates are counted from the 30%-risk frost dates above (last frost Apr 12, first frost Oct 25). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Feb 15 – Mar 1 | Apr 19 – May 3 | — | — |
| Pepper | Feb 1 – Feb 15 | Apr 26 – May 10 | — | — |
| Lettuce | Mar 1 – Mar 15 | Mar 29 – Apr 19 | Mar 15 – Apr 26 | Aug 16 – Sep 13 |
| Green Beans | — | — | Apr 19 – May 24 | Aug 2 – Aug 16 |
| Sweet Corn | — | — | Apr 19 – May 17 | — |
| Zucchini & Summer Squash | Mar 15 – Mar 22 | Apr 19 – May 3 | Apr 19 – May 10 | Aug 2 – Aug 16 |
| Cucumber | Mar 15 – Mar 22 | Apr 26 – May 3 | Apr 19 – May 10 | Aug 2 – Aug 16 |
| Carrot | — | — | Mar 22 – Apr 26 | Aug 2 – Aug 16 |
| Onion | Jan 18 – Feb 1 | Mar 15 – Mar 29 | — | — |
| Potato | — | Mar 15 – Apr 5 | — | — |
| Basil | Mar 1 – Mar 15 | Apr 26 – May 10 | Apr 26 – May 17 | — |
| Spinach | — | — | Mar 1 – Mar 29 | Aug 30 – Sep 27 |
| Kale | Feb 15 – Mar 1 | Mar 15 – Apr 5 | Mar 15 – Apr 5 | Aug 16 – Sep 13 |
| Broccoli | Feb 15 – Mar 1 | Mar 29 – Apr 19 | — | Aug 2 – Aug 16 |
| Peas | — | — | Mar 1 – Mar 22 | Aug 16 – Aug 30 |
| Eggplant | Feb 1 – Feb 15 | Apr 26 – May 10 | — | — |
| Cabbage | Feb 15 – Mar 1 | Mar 15 – Mar 29 | — | Aug 2 – Aug 16 |
| Radish | — | — | Mar 8 – Apr 26 | Sep 13 – Oct 11 |
| Strawberry | — | Mar 15 – Apr 5 | — | — |
| Beets | — | — | Mar 22 – May 3 | Aug 16 – Aug 30 |
Nearby cities in Missouri
- O'Fallon — zone 6b, last frost Apr 16, first frost Oct 20
- Springfield — zone 6b, last frost Apr 16, first frost Oct 22
- Independence — zone 6b, last frost Apr 16, first frost Oct 22
- Lee's Summit — zone 6b, last frost Apr 13, first frost Oct 23
- St. Louis — zone 7a, last frost Apr 7, first frost Oct 31
- Kansas City — zone 6b, last frost Apr 10, first frost Oct 29
More: all Missouri cities · other zone 6b cities: Columbus, OH, Indianapolis, IN, Boston, MA, Detroit, MI, Kansas City, MO, Cincinnati, OH, Pittsburgh, PA, Buffalo, NY
Columbia gardening questions
When is the last frost in Columbia, MO?
Plan around Apr 12. At NOAA's Columbia U Of M, MO station, 0.4 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 5, and after Apr 21 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 26. The 90% and 10% dates are 33 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Columbia, MO?
Start seeds indoors Feb 15 – Mar 1 and set transplants outside Apr 19 – May 3, once nights stay above 50°F and the soil is near 60°F. That leaves 196 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Columbia?
About 207 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 187 days, and in 1 year in 10 it runs 227 days or more. In fall there is a 10% chance of frost by Oct 17 and a 30% chance by Oct 25. That ranks 3rd longest of 7 Missouri cities on this site.
When should I plant a fall garden in Columbia?
Count back from the first fall frost (Oct 25): transplant broccoli Aug 2 – Aug 16; sow kale Aug 16 – Sep 13; sow lettuce Aug 16 – Sep 13; sow radishes Sep 13 – Oct 11. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 9. How the math works: succession and fall planting.
Did Columbia's hardiness zone change on the 2023 map?
Yes. Most of Columbia was zone 6a on the 2012 map and is zone 6b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
How does Columbia compare with O'Fallon, MO?
Both are in zone 6b. The typical last spring frost in Columbia (Apr 12) comes about 4 days earlier than in O'Fallon, MO (Apr 16), 87 miles away, and the first fall frost is Oct 25 versus Oct 20. The two cities use different NOAA stations.