When to plant in Vernon Hills, IL
USDA Zone 6aEverything below — frost dates, hardiness zone, and what to plant when in Vernon Hills, Illinois — is derived from the closest NOAA station with complete climate normals.
Zone 6a means Vernon Hills sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
MUNDELEIN 4 WSW · 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 Vernon Hills’s own odds, recorded at MUNDELEIN 4 WSW.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 26 | May 10 | Apr 25 | Sep 24 | Oct 9 | Oct 22 |
| 32°F | May 15 | Apr 29 | Apr 14 | Oct 4 | Oct 20 | Nov 1 |
| 28°F | May 4 | Apr 16 | Apr 2 | Oct 16 | Oct 31 | Nov 12 |
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 Vernon Hills, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 14 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.
Vernon Hills planting FAQ
When is the last spring frost in Vernon Hills, IL?
On average, the last spring frost in Vernon Hills is around April 29 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Vernon Hills, IL?
Expect Vernon Hills's first fall frost near October 20 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Vernon Hills in?
Vernon Hills 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 Vernon Hills?
There are roughly 174 frost-free days in Vernon Hills (a moderate growing season), running from the average last frost around April 29 to the first fall frost near October 20.
When should I plant tomatoes in Vernon Hills?
In Vernon Hills, start tomato seeds indoors around March 4–March 18, then transplant seedlings outdoors around May 6 once the danger of frost has passed.
Never miss a window in Vernon Hills
An email when it’s time to start seeds, transplant, and sow — timed to Vernon Hills’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Libertyville · 6 km
- Mundelein · 6 km
- Buffalo Grove · 8 km
- Lake Forest · 9 km
- Lake Zurich · 11 km
- Deerfield · 12 km
- Wheeling · 12 km
- North Chicago · 12 km
Frost dates recorded at MUNDELEIN 4 WSW, 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 Vernon Hills, IL — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00115961. Retrieved from https://blissgarden.com/illinois/vernon-hills.