When to plant in Washington, IL
USDA Zone 6aWashington, Illinois frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
These dates come from a station roughly 19 km away, the closest with full normals; terrain around Washington (elevation, water, pavement) can move your real frost dates a few days either way. In zone 6a, Washington gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
The average first fall frost in Washington is now 9 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
CONGERVILLE 2NW · 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 Washington’s own odds, recorded at CONGERVILLE 2NW.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 18 | May 2 | Apr 18 | Sep 25 | Oct 6 | Oct 19 |
| 32°F | May 7 | Apr 21 | Apr 7 | Oct 3 | Oct 17 | Oct 30 |
| 28°F | Apr 27 | Apr 9 | Mar 28 | Oct 11 | Oct 27 | Nov 10 |
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 Washington, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 35 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.
Washington planting FAQ
When is the last spring frost in Washington, IL?
Plan for the last spring frost in Washington around April 21 (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 Washington, IL?
The first fall frost in Washington typically arrives around October 17 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Washington in?
Washington is in USDA hardiness zone 6a. In zone 6a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Washington?
Washington has about 179 frost-free days — a moderate growing season — between the average last spring frost (April 21) and first fall frost (October 17).
When should I plant tomatoes in Washington?
For Washington, sow tomatoes indoors about February 24–March 10 and move the seedlings out around April 28, after the last spring frost.
Never miss a window in Washington
An email when it’s time to start seeds, transplant, and sow — timed to Washington’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- East Peoria · 10 km
- Morton · 11 km
- Peoria · 16 km
- Pekin · 22 km
- Normal · 43 km
- Bloomington · 47 km
- Canton · 53 km
- Lincoln · 62 km
Frost dates recorded at CONGERVILLE 2NW, 19 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 Washington, IL — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00111836. Retrieved from https://blissgarden.com/illinois/washington.