Onions last 1 to 2 months in the refrigerator when whole and uncut, and 7 to 10 days once they are cut, as long as they are kept at 40°F (4°C) or below. Whole onions actually keep best in a cool, dark, dry pantry, where they can last 2 to 3 months, but the fridge is the right home for cut onions and for whole onions in a warm kitchen. This guide covers exactly how long each type of onion lasts, the best way to store whole and cut onions, how to spot a bad onion, whether you can freeze onions, and answers to the most common onion-storage questions.

How Long Do Onions Last in the Fridge?

An onion's shelf life depends on whether it is whole or cut and on the variety. Whole onions keep for one to two months in the refrigerator; once you slice into one, the clock speeds up and you should use the cut onion within about a week. Store cut onions in an airtight container so they do not soak up moisture or pass their smell to butter, cheese, and other foods nearby.

Whole onions can chill in the fridge for up to two months when kept in a cool, dry spot with good airflow. But once you slice into one, cut onions last about 7 to 10 days in an airtight container. For a deeper look at sliced onions, see Fridge.com guide on how long a cut onion lasts in the fridge and, for the red variety, how long a cut red onion lasts in the fridge.

Shelf Life by Onion Type

Not all onions keep for the same length of time. Storage onions — yellow, white, and red — last the longest, while high-moisture sweet onions and delicate green onions spoil faster.

Yellow, white, and red onions can hang out in your fridge for a month or two. Sweet onions such as Vidalias have a higher water content, so they are more perishable — use them first. Green onions are the sprinters of the bunch, lasting only a week or two. If you also stock other produce, Fridge.com guides on how long a red pepper lasts in the fridge and how long a cut bell pepper lasts in the fridge follow the same storage logic.

How to Store Onions in the Fridge

How you store onions makes the difference between one that lasts two months and one that turns soft in a week. Keep your refrigerator at 40°F (4°C) or below, and use an appliance thermometer to confirm it — many fridges run warmer than the dial suggests. Store onions on a shelf or in the crisper, not in the door, which is the warmest part of the fridge.

• Temperature: Aim for 32°F to 40°F (0°C to 4°C). Cold, steady temperatures slow sprouting and spoilage.
• Humidity: Onions like it dry. Too much moisture and they turn mushy and moldy, so avoid sealed plastic bags that trap condensation.
• Air circulation: Let onions breathe. A mesh or paper bag, a perforated bag, or an open container keeps air moving and prevents mold.
• Keep them dry: Do not wash onions before storing. If they do get wet, dry them thoroughly first.
• Separate from potatoes: Onions and potatoes release gases and moisture that make each other spoil faster, so store them apart.

Storing Whole Onions

Whole onions actually last longest in a cool, dark, dry pantry, where they can keep for two to three months. In a warm kitchen, or once summer heat sets in, the fridge is the safer choice. Store whole onions in the crisper drawer or a ventilated bag in the main body of the fridge, where they will keep for one to two months.

Storing Cut Onions

Cut onions need more care. Once you slice into an onion, refrigerate it promptly — never leave cut onion at room temperature for more than two hours. Store it in an airtight container, or wrap it tightly in plastic wrap or foil with the cut side sealed, and keep it on a shelf in the main body of the fridge. Because cut onions both absorb and give off strong odors, a sealed container also protects nearby dairy and other foods. Label the container with the date you cut the onion so you know when to use it by.

For a related sealed-food example, see how long a jar of tomato sauce lasts in the fridge.

How to Tell if Your Onions Have Gone Bad

Nobody wants to slice into a spoiled onion. Use your eyes, your hands, and your nose — and when in doubt, throw it out.

Look and Feel

• Discoloration: Fresh onions have an even color. Dark spots, brown or black patches, or a greenish tint mean it is time to toss it.
• Mold: Any fuzzy or dark mold on the surface is a no-go.
• Squishy or slimy texture: Onions should be firm. Soft, mushy, or slimy onions are done.
• Sprouts: A sprouting onion is not necessarily bad. If the onion is still firm, remove the green shoot and use the rest, though it may taste slightly more bitter.

The Smell Test

Your nose knows. A fresh onion has a sharp, pungent smell. If it smells sour, rotten, or just plain off, throw it out.

One caution for cut onions: if they have been in the fridge longer than 7 to 10 days, discard them even if they still look fine. Harmful bacteria can build up before an onion looks or smells bad, so follow the time limit rather than relying on appearance alone. The same "when in doubt, throw it out" rule applies to richer leftovers — see how long a cheesecake lasts in the fridge and how long a cooked steak lasts in the fridge.

Can You Freeze Onions?

Yes — freezing is a great way to rescue extra onions. Chopped or sliced onions freeze well and keep their best quality for 3 to 6 months (they stay safe well beyond that when held at 0°F). They turn soft once thawed, so use them in cooked dishes such as soups, stews, and casseroles rather than raw. Whole raw onions do not freeze well; they become mushy when thawed.

1. Peel and chop the onions to the size you like.
2. Spread the pieces in a single layer on a baking sheet.
3. Freeze for a few hours until solid — this stops them from clumping.
4. Transfer the frozen onions to an airtight container or freezer bag and label it with the date.

Curious how other foods hold up in the freezer and fridge? See how long a ham stays good in the fridge and how long a frozen turkey lasts in the freezer.

Ways to Use Onions Before They Go Bad

Got more onions than you can use? Put them to work before they turn.

• Caramelized onions: Cook sliced onions low and slow until golden and sweet — perfect on burgers, sandwiches, and pizza.
• French onion soup: Simmer caramelized onions with beef broth, wine, and herbs, then top with cheese and toasted bread.
• Onion rings: Dip rings in batter and fry until crispy for a snack or side.
• Salsas and dips: Add finely chopped onion to salsa, guacamole, and other dips for crunch and bite.
• Stuffed onions: Hollow out large onions, fill with meat, rice, and spices, and bake until tender.
• Onion chutney: Cook onions with vinegar, sugar, and spices for a tangy condiment that keeps well and pairs with meats and cheeses.

Rounding out a meal? A squeeze of citrus brightens most onion dishes — here is how long a cut lemon lasts in the fridge.

Frequently Asked Questions

How long do onions last in the fridge?

Whole onions last 1 to 2 months in the refrigerator, and cut onions last 7 to 10 days when sealed in an airtight container. Sweet onions keep 2 to 4 weeks and green onions 1 to 2 weeks. Keep the fridge at 40°F (4°C) or below for the full storage life.

How long is a cut onion good for in the fridge?

A cut or sliced onion is good for 7 to 10 days in the fridge in an airtight container, or 5 to 7 days wrapped in plastic wrap or foil. Refrigerate it within two hours of cutting and discard it after the time limit even if it still looks fine.

How long does a red onion last in the fridge?

A whole red onion lasts 1 to 2 months in the fridge, the same as yellow and white onions. Once cut, a red onion keeps 7 to 10 days sealed in an airtight container.

How long do refrigerated onions last compared to onions on the counter?

Whole onions last 2 to 3 months in a cool, dark, dry pantry and 1 to 2 months in the fridge. The counter is best for whole onions in a cool home; the fridge is better in a warm kitchen and is required for any cut onion.

Can you store onions with other foods?

Keep onions away from potatoes and fruit. Onions release gases that speed up ripening and spoilage in nearby produce, and potatoes give off moisture that shortens onion life. Other vegetables can share space if needed.

For more produce-storage pairings, see how long a cut cucumber lasts in the fridge and how long a jar of applesauce lasts in the fridge.

Can you freeze onions?

Yes. Chop or slice onions, freeze them flat on a tray, then bag them. They keep their best quality for 3 to 6 months and are best used in cooked dishes, since they soften after thawing. Whole raw onions do not freeze well.

Do onions need to be refrigerated?

Whole onions do not have to be refrigerated — a cool, dark, dry spot with good airflow is ideal. Refrigerate whole onions if your kitchen is warm, and always refrigerate onions once they are cut.

What happens to onions in the fridge during a power outage?

Keep the door closed. A full fridge holds a safe temperature for about 4 hours during an outage. If perishable cut onions have been above 40°F for more than 2 hours, discard them — when in doubt, throw it out.

How can you tell if an onion is bad?

Toss any onion that is soft or mushy, has fuzzy or dark mold, shows brown or black spots, or smells sour or off. Sprouting alone is not spoilage — remove the shoot and use the onion if it is still firm.

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