When to plant in Wood River, IL
USDA Zone 7aEverything below — frost dates, hardiness zone, and what to plant when in Wood River, Illinois — is derived from the closest NOAA station with complete climate normals.
Zone 7a means many perennials and even some tender shrubs overwinter in Wood River, while your frost dates still decide when annuals go out.
Frost probability
ALTON - MELVIN PRICE L&D · 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 Wood River’s own odds, recorded at ALTON - MELVIN PRICE L&D.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 1 | Apr 14 | Mar 31 | Oct 12 | Oct 27 | Nov 8 |
| 32°F | Apr 19 | Apr 4 | Mar 18 | Oct 25 | Nov 5 | Nov 21 |
| 28°F | Apr 9 | Mar 25 | Mar 6 | Nov 2 | Nov 16 | Dec 1 |
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 Wood River, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 31 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.
Wood River planting FAQ
When is the last spring frost in Wood River, IL?
Wood River's average last spring frost falls near April 4 — 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 Wood River, IL?
Expect Wood River's first fall frost near November 5 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Wood River in?
Wood River 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 Wood River?
There are roughly 215 frost-free days in Wood River (a long growing season), running from the average last frost around April 4 to the first fall frost near November 5.
When should I plant tomatoes in Wood River?
In Wood River, start tomato seeds indoors around February 7–February 21, then transplant seedlings outdoors around April 11 once the danger of frost has passed.
Never miss a window in Wood River
An email when it’s time to start seeds, transplant, and sow — timed to Wood River’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Alton · 8 km
- Edwardsville · 11 km
- Spanish Lake · 14 km
- Glen Carbon · 14 km
- Granite City · 15 km
- Godfrey · 16 km
- Bellefontaine Neighbors · 18 km
- Old Jamestown · 18 km
Frost dates recorded at ALTON - MELVIN PRICE L&D, 6 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 Wood River, IL — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00110137. Retrieved from https://blissgarden.com/illinois/wood-river.