When to plant in Clayton, MO
USDA Zone 7aClayton, Missouri frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
In zone 7a, Clayton supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
ST LOUIS SCI CTR · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Clayton’s own odds, recorded at ST LOUIS SCI CTR.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 27 | Apr 12 | Mar 27 | Oct 15 | Oct 26 | Nov 7 |
| 32°F | Apr 18 | Apr 1 | Mar 14 | Oct 24 | Nov 4 | Nov 21 |
| 28°F | Apr 7 | Mar 22 | Mar 5 | Nov 2 | Nov 15 | Dec 4 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Clayton, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 15 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Clayton planting FAQ
When is the last spring frost in Clayton, MO?
Clayton's average last spring frost falls near April 1 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Clayton, MO?
Expect Clayton's first fall frost near November 4 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Clayton in?
Clayton is in USDA hardiness zone 7a. In zone 7a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Clayton?
Clayton has about 217 frost-free days — a long growing season — between the average last spring frost (April 1) and first fall frost (November 4).
When should I plant tomatoes in Clayton?
For Clayton, sow tomatoes indoors about February 4–February 18 and move the seedlings out around April 8, after the last spring frost.
Never miss a window in Clayton
An email when it’s time to start seeds, transplant, and sow — timed to Clayton’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- University City · 2 km
- Overland · 7 km
- Webster Groves · 7 km
- St. Louis · 7 km
- Creve Coeur · 10 km
- St. Ann · 10 km
- Jennings · 10 km
- Affton · 11 km
Frost dates recorded at ST LOUIS SCI CTR, 5 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Clayton, MO — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00237452. Retrieved from https://blissgarden.com/missouri/clayton.