Defiance, MO frost dates
Last spring frostApr 10median date
First fall frostOct 26median date
Growing season199 daysfrost-free
Hardiness zone6bZone 6b
How Defiance compares
- In 8 years out of 10, the last spring frost in Defiance falls between March 26 and April 26, a 31-day window. The first fall frost falls between October 12 and November 8.
- The median last frost is 2 days earlier than the Missouri median of Apr 12.
- Its 199-day growing season is longer than 60% of the 938 Missouri places with a regular frost season (state median 195 days).
- The last frost is 12 days earlier than the zone 6b median of Apr 22. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6b chart.
- The weather station records an average of 105 nights a year at or below 32°F.
- Defiance shares its weather station with O Fallon, MO, 16 km away, so the two have the same frost dates.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 26 |
| 50% (median) | April 10 |
| 10% (safe for tender plants) | April 26 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 12 |
| 50% (median) | October 26 |
| 90% (late) | November 8 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Defiance, MO
Defiance, MO frost dates — last frost Apr 10, first frost Oct 26, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Jan 16 to Jan 30Transplant outside: Mar 13 to Mar 27
Start indoors: Jan 30 to Feb 13Transplant outside: Apr 24 to May 8
Start indoors: Jan 30 to Feb 13Transplant outside: Apr 24 to May 8
Start indoors: Feb 13 to Feb 27Transplant outside: Apr 17 to May 1
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 20 to Apr 3Sow outdoors: Mar 13 to Apr 17Plant for fall: Aug 31 to Sep 28
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 13 to Mar 27Sow outdoors: Mar 13 to Mar 27Plant for fall: Aug 17 to Sep 7
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 27 to Apr 10Plant for fall: Jul 20 to Aug 10
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 20 to Apr 3Plant for fall: Jul 20 to Aug 10
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 27 to Apr 10Plant for fall: Jul 20 to Aug 10
Start indoors: Feb 27 to Mar 13Transplant outside: May 1 to May 15Sow outdoors: May 1 to May 15
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 17 to May 1
Sow outdoors: Feb 27 to Mar 20Plant for fall: Aug 3 to Aug 24
Sow outdoors: Feb 27 to Mar 20Plant for fall: Aug 31 to Sep 21
Sow outdoors: Mar 6 to Apr 17Plant for fall: Sep 14 to Oct 5
Start indoors: Mar 13 to Mar 20Transplant outside: Apr 24 to May 1Sow outdoors: Apr 17 to May 1Plant for fall: Aug 10 to Aug 24
Start indoors: Mar 13 to Mar 20Sow outdoors: Apr 17 to May 1Plant for fall: Aug 17 to Aug 31
Start indoors: Mar 13 to Mar 20Sow outdoors: Apr 17 to May 1
Start indoors: Mar 13 to Mar 20Transplant outside: Apr 24 to May 8
Sow outdoors: Mar 20 to Apr 17Plant for fall: Aug 3 to Aug 17
Sow outdoors: Mar 20 to Apr 17Plant for fall: Aug 17 to Aug 31
Sow outdoors: Mar 20 to Apr 10
Sow outdoors: Mar 27 to Apr 24Plant for fall: Aug 17 to Aug 31
Sow outdoors: Mar 27 to Apr 17Plant for fall: Aug 31 to Sep 21
Sow outdoors: Apr 17 to May 8Plant for fall: Aug 10 to Aug 24
Sow outdoors: Apr 17 to May 1
Transplant outside: Apr 24 to May 15
Plant for fall: Oct 12 to Nov 16
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Defiance, MO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 16 – Jan 30 | Mar 13 – Mar 27 | — | — |
| Peppers | Jan 30 – Feb 13 | Apr 24 – May 8 | — | — |
| Eggplant | Jan 30 – Feb 13 | Apr 24 – May 8 | — | — |
| Tomatoes | Feb 13 – Feb 27 | Apr 17 – May 1 | — | — |
| Lettuce | Feb 13 – Feb 27 | Mar 20 – Apr 3 | Mar 13 – Apr 17 | Aug 31 – Sep 28 |
| Kale | Feb 13 – Feb 27 | Mar 13 – Mar 27 | Mar 13 – Mar 27 | Aug 17 – Sep 7 |
| Broccoli | Feb 13 – Feb 27 | Mar 27 – Apr 10 | — | Jul 20 – Aug 10 |
| Cabbage | Feb 13 – Feb 27 | Mar 20 – Apr 3 | — | Jul 20 – Aug 10 |
| Cauliflower | Feb 13 – Feb 27 | Mar 27 – Apr 10 | — | Jul 20 – Aug 10 |
| Okra | Feb 27 – Mar 13 | May 1 – May 15 | May 1 – May 15 | — |
| Basil | Feb 27 – Mar 13 | Apr 17 – May 1 | — | — |
| Peas | — | — | Feb 27 – Mar 20 | Aug 3 – Aug 24 |
| Spinach | — | — | Feb 27 – Mar 20 | Aug 31 – Sep 21 |
| Radishes | — | — | Mar 6 – Apr 17 | Sep 14 – Oct 5 |
| Cucumbers | Mar 13 – Mar 20 | Apr 24 – May 1 | Apr 17 – May 1 | Aug 10 – Aug 24 |
| Zucchini & Summer Squash | Mar 13 – Mar 20 | — | Apr 17 – May 1 | Aug 17 – Aug 31 |
| Winter Squash & Pumpkins | Mar 13 – Mar 20 | — | Apr 17 – May 1 | — |
| Melons & Watermelon | Mar 13 – Mar 20 | Apr 24 – May 8 | — | — |
| Carrots | — | — | Mar 20 – Apr 17 | Aug 3 – Aug 17 |
| Beets | — | — | Mar 20 – Apr 17 | Aug 17 – Aug 31 |
| Potatoes | — | — | Mar 20 – Apr 10 | — |
| Swiss Chard | — | — | Mar 27 – Apr 24 | Aug 17 – Aug 31 |
| Cilantro | — | — | Mar 27 – Apr 17 | Aug 31 – Sep 21 |
| Green Beans | — | — | Apr 17 – May 8 | Aug 10 – Aug 24 |
| Sweet Corn | — | — | Apr 17 – May 1 | — |
| Sweet Potatoes | — | Apr 24 – May 15 | — | — |
| Garlic | — | — | — | Oct 12 – Nov 16 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Weldon Spring Nws, MO weather station, 13 km away (elevation 610 ft (186 m)).
Frost dates near Defiance
- New Melle Apr 10 · Oct 26
- Saint Albans Apr 12 · Oct 23
- Augusta Apr 8 · Oct 25
- Foristell Apr 14 · Oct 23
- Lake Saint Louis Apr 10 · Oct 26
- Wentzville Apr 10 · Oct 26
- Dutzow Apr 8 · Oct 25
- O Fallon Apr 10 · Oct 26
- Labadie Apr 8 · Oct 25
- Glencoe Apr 12 · Oct 23
Frequently asked questions
When is the last frost in Defiance, MO?
The median last spring frost in Defiance, MO is April 10. There is still about a 10% chance of frost after April 26, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Defiance, MO?
The median first fall frost is October 26, with about a 10% chance of frost before October 12.
How long is the growing season in Defiance, MO?
About 199 days between the median last spring frost and first fall frost.
What planting zone is Defiance, MO?
Defiance, MO is in USDA hardiness zone 6b.