Illinois · Garden vegetables

Onion season in Illinois

Typically early July to mid-September, with peak mid-July through mid-August.

Hatched chalk = early and late shoulders; solid = peak.

Southern Illinois runs about two weeks ahead of Chicagoland.

At a glance

Early

From early July — first pickings, lighter supply, best prices come later.

Peak

mid-July through mid-August — full stalls, full flavor. This is the stretch to plan around.

Late

Through mid-September — quantity for preserving, and the stalls start dealing.

Season length

about 11 weeks end to end, shoulders included.

Onions

Look: Dry, papery skins with a tight, small neck and no green sprout poking from the top.
Feel: Rock hard through the shoulders — any softness at the neck means rot is starting inside.
Smell: Mild and faintly sweet through the skin; a strong oniony or musty smell signals a bruised or rotting bulb.
Tip: For sweets like Vidalias, pick the flattest bulbs on the table — the flatter the disc, the milder the bite.
Keeps: Cool, dark, dry pantry — storage types keep for months, sweet onions only a few weeks.

Chasing the season?

Onion peak moves across the map. After this window, it lands next in:

The whole national sweep · everything in season in Illinois

Frequently asked questions

When is onion season in Illinois?

In Illinois, the onion season typically runs early July to mid-September, with peak availability mid-July through mid-August. Exact weeks shift a little with each year's weather.

Can I pick my own onions in Illinois?

U-pick onion fields are basically unheard of — buy braids and bags straight off the farm stand. The best market weeks are mid-July through mid-August.

How long does onion season last in Illinois?

about 11 weeks end to end — early July to mid-September. The early and late shoulders are real but lighter; the solid stretch of chalk on the band is the sure bet.