When to plant in Affton, MO
USDA Zone 7aAffton, Missouri frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Zone 7a means many perennials and even some tender shrubs overwinter in Affton, while your frost dates still decide when annuals go out.
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 Affton’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 Affton, 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.
Affton planting FAQ
When is the last spring frost in Affton, MO?
Plan for the last spring frost in Affton around April 1 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Affton, MO?
Expect Affton'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 Affton in?
Affton 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 Affton?
There are roughly 217 frost-free days in Affton (a long growing season), running from the average last frost around April 1 to the first fall frost near November 4.
When should I plant tomatoes in Affton?
In Affton, start tomato seeds indoors around February 4–February 18, then transplant seedlings outdoors around April 8 once the danger of frost has passed.
Never miss a window in Affton
An email when it’s time to start seeds, transplant, and sow — timed to Affton’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at ST LOUIS SCI CTR, 10 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 Affton, MO — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00237452. Retrieved from https://blissgarden.com/missouri/affton.