USDA zone 6a in Missouri
USDA plant hardiness zone 6a covers 46 locations across Missouri (average annual extreme minimum −10 to −5 °F): Albany, MO, Bethany, MO, Brookfield, MO, Brunswick, MO, Cameron, MO, Carrollton, MO, and 40 more. Average last spring frost across this group ranges April 4 (Kansas) to April 26 (Steelville), and growing seasons run 164–211 days (Steelville to Kansas) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Missouri location's own frost dates; the printable planting calendar uses Bethany, this group's median-season location.
- USDA zone
- 6a−10 to −5 °F
- Last frost range
- Apr 4–Apr 26avg, 32°F
- First frost range
- Oct 8–Nov 2avg, 32°F
- Growing season range
- 164–211days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Albany | — | Albany | Apr 17 | Oct 21 | 185 |
| Bethany * | McFall, Coffey | Bethany | Apr 16 | Oct 22 | 186 |
| Brookfield | Marceline, Laclede, Bucklin, Meadville, Winigan, Sumner, +1 more | Brookfield | Apr 14 | Oct 23 | 192 |
| Brunswick | Bosworth, De Witt, Triplett, Dalton, Mendon | Brunswick | Apr 10 | Oct 29 | 201 |
| Cameron | Lathrop, Hamilton, Polo, Braymer, Breckenridge, Kingston, +3 more | Hamilton 2w | Apr 23 | Oct 17 | 175 |
| Carrollton | Norborne, Bogard, Tina | Carrollton | Apr 16 | Oct 23 | 187 |
| Chillicothe | Utica, Chula, Lock Springs | Chillicothe Agri-sci | Apr 15 | Oct 21 | 188 |
| Columbia | — | Columbia U Of M | Apr 5 | Oct 31 | 207 |
| Cosby | — | Cosby 2w | Apr 17 | Oct 19 | 184 |
| Dawn | Utica, Hale, Wheeling, Ludlow | Chillicothe 2s | Apr 15 | Oct 21 | 187 |
| Edina | Philadelphia, La Belle, Ewing, Lewistown, Newark, Leonard, +3 more | Steffenville | Apr 17 | Oct 19 | 184 |
| Gallatin | Pattonsburg, Jamesport, Winston, Altamont, Jameson | Gallatin 1w | Apr 19 | Oct 21 | 184 |
| Gilman | Spickard | Spickard 7 W | Apr 20 | Oct 16 | 177 |
| Graham | — | Maryville 2e | Apr 19 | Oct 17 | 180 |
| Hannibal | Payson | Hannibal Wtr Wks | Apr 10 | Oct 27 | 199 |
| Harris | — | Princeton | Apr 25 | Oct 15 | 174 |
| Huntsville | Cairo, Jacksonville | Moberly | Apr 13 | Oct 25 | 195 |
| Kansas | Liberty, Pleasant Valley | Kansas City Downtown Ap | Apr 4 | Nov 2 | 211 |
| Kearney | Excelsior Springs, Lawson | Kearney 3e | Apr 19 | Oct 17 | 181 |
| King | Maysville, Stewartsville, Osborn, Clarksdale, Union Star, Amity, +1 more | Amity 4 Ne | Apr 19 | Oct 19 | 180 |
| Kirksville | Queen, Greentop, Novinger, Green Castle, Brashear, Worthington | Kirksville | Apr 21 | Oct 19 | 179 |
| La Grange | Wayland, Williamstown, Monticello, Meyer, Lima, Marcelline | Canton L&d 20 | Apr 11 | Oct 23 | 194 |
| La Plata | Hurdland, Elmer, Gibbs, Ethel | Kirksville Rgnl Ap | Apr 19 | Oct 18 | 180 |
| Liberty | Buckner, River Bend, Orrick, Missouri, Sibley, Levasy | Independence | Apr 10 | Oct 27 | 198 |
| Liberty | Smithville, Plattsburg, Edgerton, Gower, Trimble, Holt | Smithville Lake | Apr 18 | Oct 20 | 183 |
| Linneus | Browning, Purdin | Chillicothe 22 Ene | Apr 15 | Oct 20 | 184 |
| Louisiana | St. Clement | Bowling Green 1 E | Apr 13 | Oct 23 | 188 |
| Macon | Clarence, Bevier, New Cambria, Callao, Atlanta, Excello | Long Branch Rsvr | Apr 8 | Oct 28 | 201 |
| Memphis | Downing, Wyaconda, South Gorin, Luray, Granger, Rutledge, +1 more | Memphis | Apr 23 | Oct 17 | 176 |
| Milan | — | Green City 5n | Apr 26 | Oct 14 | 169 |
| Monroe | — | Monroe City | Apr 12 | Oct 22 | 190 |
| Mound | Forest, Oregon, White Cloud, Maitland, Fillmore | Oregon | Apr 16 | Oct 20 | 186 |
| Newburg | — | Rolla Missouri S&t | Apr 5 | Nov 1 | 207 |
| Oak Grove | Napoleon, Bates | Elm | Apr 13 | Oct 23 | 191 |
| Perry | Center, Curryville, Florida | Vandalia | Apr 11 | Oct 23 | 192 |
| Rayville | — | Richmond 3s | Apr 19 | Oct 18 | 180 |
| Richmond | Lexington, Wellington, Hardin, Henrietta, Camden | Lexington 3e | Apr 8 | Oct 25 | 197 |
| Salisbury | Keytesville, Clifton Hill | Salisbury | Apr 12 | Oct 22 | 190 |
| Shelbina | Paris, Clarence, Shelbyville, Hunnewell, Holliday, Florida | Shelbina | Apr 21 | Oct 17 | 177 |
| St. Joseph | Country Club, Agency, Savannah, Elwood, Wathena, Faucett, +2 more | St Joseph Rosecrans Ap | Apr 19 | Oct 17 | 180 |
| Stanberry | Conception, Darlington, Bolckow, Conception Junction, Rosendale, Clyde, +3 more | Conception | Apr 17 | Oct 20 | 184 |
| Steelville | — | Steelville 2 N | Apr 26 | Oct 8 | 164 |
| Steelville | — | Salem | Apr 17 | Oct 18 | 182 |
| Strasburg | — | Pleasant Hill Wfo | Apr 8 | Oct 29 | 204 |
| Trenton | Galt, Laredo, Humphreys | Trenton | Apr 16 | Oct 20 | 184 |
| Weston | Dearborn, Camden Point, Ferrelview | Kansas City Intl Ap | Apr 13 | Oct 24 | 193 |
* Bethany is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Bethany, representative)
Computed from Bethany's average frost dates — the median-season location in this Missourizone 6a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Feb 19 – Mar 5 | Apr 23 – Apr 30 | Jun 22 – Jul 12 | — | matures comfortably |
| Pepper | Very tender | Feb 5 – Feb 19 | Apr 30 – May 7 | Jun 29 – Jul 29 | — | matures comfortably |
| Cucumber | Tender | Mar 19 – Mar 26 | Apr 23 – Apr 30 | Jun 12 – Jul 2 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 23 – Apr 30 | Jun 7 – Jun 22 | — | matures comfortably |
| Bush bean | Tender | — | Apr 23 – Apr 30 | Jun 12 – Jun 22 | Aug 23 – Sep 2 | matures comfortably |
| Sweet corn | Tender | — | Apr 16 – Apr 30 | Jun 15 – Jul 15 | — | matures comfortably |
| Basil | Very tender | Mar 5 – Mar 19 | Apr 23 – Apr 30 | May 23 – Jun 7 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 5 – Mar 19 | Mar 19 – Apr 2 | May 3 – May 18 | Aug 9 – Aug 24 | matures comfortably |
| Pea | Hardy | — | Mar 5 – Mar 19 | Apr 29 – May 14 | Jul 30 – Aug 14 | matures comfortably |
| Spinach | Hardy | — | Mar 5 – Mar 19 | Apr 14 – Apr 24 | Aug 19 – Aug 29 | matures comfortably |
| Carrot | Half-hardy | — | Mar 26 – Apr 2 | May 25 – Jun 14 | Jul 20 – Aug 9 | matures comfortably |
| Broccoli | Half-hardy | Feb 19 – Mar 5 | Mar 19 – Apr 2 | May 13 – Jun 2 | Jul 25 – Aug 14 | matures comfortably |
Which crops fit this growing season
Using Bethany's own 186-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Bethany)
From NOAA's 1991–2020 Climate Normals at station USC00230608. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Apr 29 | May 13 | Oct 12 | Oct 25 | 165 |
| 32°F (freeze) | Apr 16 | May 3 | Oct 22 | Nov 2 | 186 |
| 28°F | Apr 5 | Apr 21 | Oct 31 | Nov 13 | 208 |
| 24°F | Mar 28 | Apr 11 | Nov 9 | Nov 26 | 226 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 46 locations is 3,702; Bethany's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 3,530 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 5,801 | cool-season crops (brassicas, greens) |
Hardiness zone 6a in Missouri
Zone 6a means an average annual extreme minimum winter temperature of about −10 to −5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Missouri spans 6 hardiness zones in this dataset — see all Missouri locations for the full range, including zones5b, 6b, 7a, 7b, 8a.
Explore zone 6a in other states at zone 6a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 6a mean in Missouri?
- Zone 6a means an average annual extreme minimum winter temperature of −10 to −5 °F — the standard USDA measure of which perennials survive winter. 46 locations in Missouri fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Missouri's zone 6a is the growing season longest?
- Kansas runs the longest season on this page at about 211 days; Steelville is shortest at about 164 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Missouri's zone 6a?
- Using Bethany's frost dates (this page's median-season location): start seeds indoors about Feb 19 – Mar 5, then transplant outside about Apr 23 – Apr 30. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Missouri's zone 6a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 46 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.