Flinthill, MO frost dates
How Flinthill compares
- In 8 years out of 10, the last spring frost in Flinthill falls between March 27 and April 25, a 29-day window. The first fall frost falls between October 14 and November 7.
- The median last frost is 3 days earlier than the Missouri median of Apr 12.
- Its 200-day growing season is longer than 62% of the 938 Missouri places with a regular frost season (state median 195 days).
- The last frost is 13 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 103 nights a year at or below 32°F.
- Flinthill shares its weather station with Saint Charles, MO, 2 km away, so the two have the same frost dates.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 27 |
| 50% (median) | April 9 |
| 10% (safe for tender plants) | April 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 14 |
| 50% (median) | October 26 |
| 90% (late) | November 7 |
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 Flinthill, MO
Flinthill, MO frost dates — last frost Apr 9, first frost Oct 26, zone 6b. whenisthelastfrost.com
When to plant vegetables in Flinthill, MO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 15 – Jan 29 | Mar 12 – Mar 26 | — | — |
| Peppers | Jan 29 – Feb 12 | Apr 23 – May 7 | — | — |
| Eggplant | Jan 29 – Feb 12 | Apr 23 – May 7 | — | — |
| Tomatoes | Feb 12 – Feb 26 | Apr 16 – Apr 30 | — | — |
| Lettuce | Feb 12 – Feb 26 | Mar 19 – Apr 2 | Mar 12 – Apr 16 | Aug 31 – Sep 28 |
| Kale | Feb 12 – Feb 26 | Mar 12 – Mar 26 | Mar 12 – Mar 26 | Aug 17 – Sep 7 |
| Broccoli | Feb 12 – Feb 26 | Mar 26 – Apr 9 | — | Jul 20 – Aug 10 |
| Cabbage | Feb 12 – Feb 26 | Mar 19 – Apr 2 | — | Jul 20 – Aug 10 |
| Cauliflower | Feb 12 – Feb 26 | Mar 26 – Apr 9 | — | Jul 20 – Aug 10 |
| Okra | Feb 26 – Mar 12 | Apr 30 – May 14 | Apr 30 – May 14 | — |
| Basil | Feb 26 – Mar 12 | Apr 16 – Apr 30 | — | — |
| Peas | — | — | Feb 26 – Mar 19 | Aug 3 – Aug 24 |
| Spinach | — | — | Feb 26 – Mar 19 | Aug 31 – Sep 21 |
| Radishes | — | — | Mar 5 – Apr 16 | Sep 14 – Oct 5 |
| Cucumbers | Mar 12 – Mar 19 | Apr 23 – Apr 30 | Apr 16 – Apr 30 | Aug 10 – Aug 24 |
| Zucchini & Summer Squash | Mar 12 – Mar 19 | — | Apr 16 – Apr 30 | Aug 17 – Aug 31 |
| Winter Squash & Pumpkins | Mar 12 – Mar 19 | — | Apr 16 – Apr 30 | — |
| Melons & Watermelon | Mar 12 – Mar 19 | Apr 23 – May 7 | — | — |
| Carrots | — | — | Mar 19 – Apr 16 | Aug 3 – Aug 17 |
| Beets | — | — | Mar 19 – Apr 16 | Aug 17 – Aug 31 |
| Potatoes | — | — | Mar 19 – Apr 9 | — |
| Swiss Chard | — | — | Mar 26 – Apr 23 | Aug 17 – Aug 31 |
| Cilantro | — | — | Mar 26 – Apr 16 | Aug 31 – Sep 21 |
| Green Beans | — | — | Apr 16 – May 7 | Aug 10 – Aug 24 |
| Sweet Corn | — | — | Apr 16 – Apr 30 | — |
| Sweet Potatoes | — | Apr 23 – May 14 | — | — |
| 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 St Peters 2 Se, MO weather station, 5 km away (elevation 574 ft (175 m)).
Frost dates near Flinthill
- Saint Charles Apr 9 · Oct 26
- Earth City Apr 8 · Oct 29
- Saint Peters Apr 9 · Oct 26
- Maryland Heights Apr 2 · Nov 4
- Cottleville Apr 10 · Oct 26
- Bridgeton Apr 2 · Nov 4
- Chesterfield Apr 4 · Oct 29
- Saint Ann Apr 2 · Nov 4
- Hazelwood Apr 2 · Nov 4
- Ballwin Apr 4 · Oct 29
Frequently asked questions
When is the last frost in Flinthill, MO?
The median last spring frost in Flinthill, MO is April 9. There is still about a 10% chance of frost after April 25, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Flinthill, MO?
The median first fall frost is October 26, with about a 10% chance of frost before October 14.
How long is the growing season in Flinthill, MO?
About 200 days between the median last spring frost and first fall frost.
What planting zone is Flinthill, MO?
Flinthill, MO is in USDA hardiness zone 6b.