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When to plant in River Grove, IL

USDA Zone 6a

River Grove, Illinois frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.

In zone 6a, River Grove gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.

Station · CHICAGO OHARE INTL AP · 11.2 km
Last spring frost
April 16
50% chance · 32°F
First fall frost
October 28
50% chance · 32°F
Growing season
195 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for River GroveA year-band showing 32°F frost risk from January to December for River Grove: last spring frost around April 16, first fall frost around October 28, about 195 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average first fall frost in River Grove is now 9 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

CHICAGO OHARE INTL AP · 1991–2020

The 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 River Grove’s own odds, recorded at CHICAGO OHARE INTL AP.

Frost-probability curves for River GroveProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around April 16 and the first fall frost around October 28, giving about 195 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMay 13Apr 29Apr 15Oct 3Oct 18Oct 30
32°FMay 1Apr 16Apr 3Oct 15Oct 28Nov 11
28°FApr 19Apr 5Mar 21Oct 27Nov 7Nov 22

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Brussels Sprouts
July 8July 22
Fall sowin 3 days
Rutabaga
July 22August 5
Fall sowin 17 days
Broccoli
August 5August 19
Fall sowin 17 days
Cabbage
August 5August 19
Fall sowin 17 days
Carrot
August 5August 19
Fall sowin 17 days
Cauliflower
August 5August 19
Fall sowin 17 days
Napa Cabbage
August 5September 2

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in River Grove, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 20 km · complete 32°F normals

When 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.

CHICAGO OHARE INTL AP
Primary
11 km · 201 m elevation
SPRING
Apr 16
FALL
Oct 28
CHICAGO MIDWAY AP
17 km · 187 m elevation
SPRING
Apr 11
FALL
Oct 31
CHICAGO NORTHERLY IS
20 km · 178 m elevation
SPRING
Apr 10
FALL
Nov 5

River Grove planting FAQ

When is the last spring frost in River Grove, IL?

On average, the last spring frost in River Grove is around April 16 (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 River Grove, IL?

Expect River Grove's first fall frost near October 28 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is River Grove in?

River Grove 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 River Grove?

River Grove has about 195 frost-free days — a moderate growing season — between the average last spring frost (April 16) and first fall frost (October 28).

When should I plant tomatoes in River Grove?

For River Grove, sow tomatoes indoors about February 19–March 5 and move the seedlings out around April 23, after the last spring frost.

Planting reminders

Never miss a window in River Grove

An email when it’s time to start seeds, transplant, and sow — timed to River Grove’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at CHICAGO OHARE INTL AP, 11 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in River Grove, IL — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094846. Retrieved from https://blissgarden.com/illinois/river-grove.
When to Plant in River Grove, IL — Frost Dates & Zone 6a — BlissGarden