Left Eggs in Your Car? How Long They Stay Safe and What to Do

It happens to everyone eventually: you unpack the shopping, and the eggs are still sitting in the boot. Whether they are worth keeping depends on two things, how long they were out of the fridge and how hot or cold the car got.

How long can eggs stay in a car?

US food safety agencies give the clearest rule. The USDA says refrigerated eggs should not be left out for more than 2 hours. FoodSafety.gov tightens that to 1 hour when the eggs are exposed to temperatures above 32°C (90°F), and it names a hot car as the example.

Where the eggs were	How long	What to do
Cool car, under 32°C (90°F)	Up to 2 hours	Put them back in the fridge and use as normal
Cool car, under 32°C (90°F)	More than 2 hours	Throw them out
Hot car, over 32°C (90°F)	Up to 1 hour	Put them back in the fridge and use as normal
Hot car, over 32°C (90°F)	More than 1 hour, or overnight	Throw them out
Freezing car, shells cracked	Any time	Throw them out
Freezing car, shells intact	Any time	Keep frozen, thaw in the fridge, cook thoroughly

These times assume the eggs were bought cold from a refrigerated shelf, which is how nearly all eggs are sold in the US and how most Australians store them at home.

How hot does a parked car get?

Hotter and faster than most people expect. A 2018 study by Arizona State University and UC San Diego parked cars in the sun on days over 35°C (95°F) and found the cabin air averaged about 47°C (116°F) after an hour. Cars parked in the shade still reached about 38°C (100°F).

It is not only a summer problem. A 2005 Stanford study found that even on a 22°C (72°F) day, the inside of a parked car warmed by about 22°C (40°F) in an hour, with most of the rise in the first 30 minutes. So on a mild, sunny day, eggs in the car can pass the 32°C mark well inside the 1 hour limit.

Why does it matter if cold eggs warm up?

Two reasons. The first is the temperature danger zone. The USDA puts it at 4 to 60°C (40 to 140°F) and says bacteria grow fastest in that range, doubling in as little as 20 minutes. Australia’s food authorities use 5 to 60°C.

The second is condensation. The USDA explains that a cold egg left at room temperature can “sweat”, and that moisture helps bacteria move from the shell into the egg. Australian Eggs says the same: eggs moved from the fridge to a warmer spot sweat, which gives bacteria a chance to get through the shell. A sealed car warming up in the sun is a good way to make eggs sweat.

The bacteria of concern is Salmonella. The FDA notes that even clean, unbroken, fresh eggs can carry Salmonella Enteritidis inside, so a normal-looking egg tells you nothing about its safety.

Why do US eggs need the fridge when some countries don’t?

It comes down to washing. US eggs must be washed at the processing plant, and the USDA says this removes the cuticle, or “bloom”, a natural coating that helps seal the pores in the shell. Once that is gone, the egg depends on refrigeration, and US rules require eggs to be stored and transported at 7°C (45°F) or below.

In the UK and EU, Class A eggs must not be washed, and most UK eggs carry the British Lion mark, a scheme started in 1998 that vaccinates hens against Salmonella. That is why eggs often sit on an unrefrigerated shelf in British and European supermarkets. Once an egg has been refrigerated, though, the sweating problem applies wherever you live.

What is the advice in Australia?

Australian Eggs, the industry body, says eggs should always be refrigerated in Australia: in their carton, on a middle shelf rather than in the door. It also says not to leave refrigerated eggs out for more than two hours, for the condensation reason above.

Fridge storage is not yet required all the way along the supply chain. Food Standards Australia New Zealand has noted that refrigeration in shops is up to the retailer, and its Board approved new egg safety requirements in September 2025, including temperature control during storage and transport. At home, the NSW Food Authority’s general rule for cold food is to keep it at or below 5°C.

What should you do if the eggs froze in the car?

The USDA says shell eggs should not be frozen, but if one freezes by accident:

What happened	What to do
Shell cracked while freezing	Throw the egg out
Shell intact	Keep it frozen until needed, then thaw it in the fridge
Thawed, shell intact	Best hard boiled, as the yolk goes thick and syrupy

Frozen eggs crack because the inside expands, so check every egg in the carton, not just the top row.

Do eggs left out lose quality as well as safety?

Yes. A study in the Journal of Food, Agriculture and Environment stored fresh eggs either in a fridge at 4°C or at room temperature of 28 to 31°C, and measured the Haugh unit, a standard score of how firm and fresh the white is.

Days stored	Fridge at 4°C	Room temperature, 28 to 31°C
0	78	78
7	73	55
14	69	48
28	64	44

Warm eggs lost freshness several times faster. That study measured quality, not bacteria, so it says nothing about whether warm eggs are safe to eat (source: Journal of Food, Agriculture and Environment).

How do you check eggs that were left in the car?

Start with the clock and the weather rather than the eggs. If they were within the time limits in the first table, put them back in the fridge. If you are not sure how long they were out, or the car was hot, the safe call is to throw them out.

Looking, sniffing or floating the eggs will not tell you if they are safe. Nebraska Extension explains that an egg floats because its air cell has grown with age, and a floating egg may still be perfectly safe to use. Salmonella does not change how an egg looks or smells. Any eggs you keep should be cooked until the yolk and white are firm, and egg dishes to 71°C (160°F), which is the FDA’s advice for all eggs.

FAQs

Are eggs left in the car overnight safe to eat?

No, not if they were refrigerated eggs from the shop. Overnight is well past the 2 hour limit, so US food safety advice is to throw them out, whatever the temperature was.

Can I put eggs back in the fridge after they have been out?

Yes, if they were out for less than 2 hours, or less than 1 hour in heat over 32°C (90°F). Put them straight back in the carton on a middle shelf.

Are unwashed farm eggs okay in a warm car?

Unwashed eggs still have their cuticle, but heat is the problem in a car, and if they had already been refrigerated they will sweat as they warm. Treat them the same as shop eggs and use the same time limits.

Does cooking make eggs safe if they were left out too long?

Cooking eggs until firm kills Salmonella, but food safety agencies do not give a cooking rule that makes eggs safe after they have been left in the danger zone too long. The advice is to throw them out rather than rely on cooking.

What about hard boiled eggs left in the car?

The same limits apply to cooked eggs: no more than 2 hours out of the fridge, or 1 hour above 32°C (90°F). The FDA’s advice covers cooked eggs and egg dishes as well as raw ones.

For more on how long food lasts out of the fridge, see how long ice cream can be left out and how long meal prep lasts in the fridge. If eggs tend to disagree with you, we also cover whether boiled eggs cause gas.

Next read: how long ice cream can safely be left out, and whether you can refreeze it.