How long can food be ok when power goes out? An emergency guide

January 13, 2026 •

4 min read

According to the Food and Drug Administration (FDA), a refrigerator will keep food safe for about 4 hours during a power outage, provided the door is kept closed. Learning how long can food be ok when power goes out is crucial for preventing foodborne illness in your household.

Quick Summary

A refrigerator's contents are safe for up to four hours, while a full freezer holds temperature for about 48 hours, or 24 if half-full. The key is keeping doors closed. After power is restored, check temperatures with a thermometer to determine what is safe to keep, refreeze, or discard.

Key Points

Refrigerator Safety: Food in a closed refrigerator is safe for about 4 hours; after that, discard all perishable items.
Freezer Safety: A full, closed freezer can keep food safe for up to 48 hours, while a half-full one lasts about 24 hours.
The Danger Zone: The temperature range between 40°F and 140°F is where harmful bacteria grow fastest; avoid this range for refrigerated food.
Use a Thermometer: The only reliable way to check food safety after an outage is with an appliance thermometer. Never trust sight or smell alone.
When in Doubt, Throw it Out: If you're unsure about the temperature or duration of an outage, always discard perishable food to avoid foodborne illness.

Understanding the Temperature 'Danger Zone'

When the electricity fails, the clock starts ticking for your refrigerated and frozen food. The primary concern is preventing bacteria from multiplying to dangerous levels. The 'Danger Zone' is the temperature range between 40°F (4°C) and 140°F (60°C), where bacteria can double in as little as 20 minutes. Keeping food below this zone (or heating it above) is essential for safety. When the power goes out, the goal is to keep your appliances in the safe zone for as long as possible.

Refrigerator vs. Freezer: What to Expect

The survival time for food varies significantly between your refrigerator and freezer. An unopened refrigerator will keep food cold for approximately four hours. After that, perishable foods like meat, poultry, fish, eggs, and leftovers that have been above 40°F (4°C) for more than two hours should be discarded.

Your freezer offers a longer window of safety, acting like a large, well-insulated cooler. A full, unopened freezer will keep food frozen for about 48 hours, while a half-full freezer will maintain its temperature for around 24 hours. Again, minimizing how often you open the door is critical to preserving the cold air inside.

Preparing for a Power Outage

Before an outage strikes, some simple steps can greatly increase your food's shelf life:

Have thermometers ready: Place an appliance thermometer in your refrigerator and freezer. This is the only reliable way to know if your food has stayed in a safe temperature range once the power returns.
Keep coolers handy: Have a few coolers and frozen gel packs on hand for transferring perishable food if the outage extends beyond the four-hour mark for your fridge.
Create more ice: In anticipation of an outage, freeze refrigerated items you won't need immediately, like milk or leftovers. Also, freeze water in clean plastic containers to fill empty space in your freezer and act as additional cold mass.
Know where to find dry ice: If the outage is predicted to be long, locating a source for dry ice can save your frozen goods. Fifty pounds of dry ice can keep a fully-stocked 18-cubic-foot freezer cold for two days.

What to Do During a Power Outage

Once the power is out, your actions can determine how much food you save:

Leave the doors closed: Avoid opening the refrigerator and freezer doors as much as possible. Every time the door is opened, cold air escapes, and warm air enters.
Group foods together: In a partially-filled freezer, group food packages together to help them stay cold longer. This is like creating a large, solid block of ice.
Move items to the freezer: If the outage is unexpected and you realize it will last more than four hours, move high-risk refrigerated items like raw meat and dairy into the freezer to extend their safe period.

After the Power Returns: When to Keep and When to Toss

Once power is restored, it's time for an assessment. The golden rule is: When in doubt, throw it out. Never taste food to determine if it is safe to eat. Even if it looks and smells okay, it could harbor dangerous bacteria.

What to do with frozen food

If the freezer thermometer reads 40°F (4°C) or below, the food is safe and can be refrozen.
If there are still ice crystals on the food, it is safe to refreeze or cook, though quality might suffer.
If the food has completely thawed and has been above 40°F (4°C) for over two hours, discard it.

Disposing of large amounts of food

If you have a significant amount of food to throw away, seal it in garbage bags and place it in a cooler with dry ice or at the curb immediately to minimize odors and prevent pest issues.

Keeping an Eye on Specific Items

Here is a quick reference table to help you decide what stays and what goes after a power outage, following FDA recommendations.


Food Type	Keep	Discard
Meat, Poultry, Fish	Frozen solid, ice crystals present	Thawed, above 40°F for >2 hrs
Dairy	Hard cheese, butter, margarine	Milk, soft cheese, sour cream, yogurt
Eggs		Fresh eggs, egg dishes
Fruits & Vegetables	Uncut fresh fruits/veg	Cut fresh fruits/veg, cooked veg
Processed Foods	Hard cheese, processed cheese	Shredded or low-fat cheese
Breads & Pastries	Breads, rolls, muffins (without custard)	Cream-filled pastries, cheesecakes
Condiments	Peanut butter, ketchup, mustard, jelly	Opened mayo, creamy dressings (if >50°F for >8 hrs)

Conclusion

Knowing how long can food be ok when power goes out is a critical part of emergency preparedness. The safety rules are simple: A refrigerator will hold safe temperatures for about 4 hours, and a full freezer for 48 hours, as long as you keep the doors shut. After power is restored, a quick temperature check is the most reliable method for determining if food is still safe. For any perishable items that have warmed to above 40°F, the safest course of action is to discard them to prevent foodborne illness. Preparation is key, and having thermometers, coolers, and extra ice on hand can make all the difference in an emergency.

To learn more about food safety during emergencies, check out the resources from FoodSafety.gov.(https://www.foodsafety.gov/food-safety-charts/food-safety-during-power-outage)

Frequently Asked Questions

A refrigerator will keep food at a safe temperature for approximately 4 hours, provided the door is kept closed. After this time, any perishable foods like meat, dairy, or leftovers should be thrown out.

A full, unopened freezer will keep food frozen for about 48 hours. If the freezer is half-full, the food is safe for about 24 hours, again assuming the door remains closed.

You should discard all perishable food from your refrigerator if it has been exposed to temperatures above 40°F (4°C) for more than two hours. It is safest to assume this after a 4-hour power outage.

You can safely refreeze food if it still contains ice crystals or is 40°F (4°C) or below. However, be aware that the texture and quality may suffer after being refrozen.

Preparation includes placing appliance thermometers in your fridge and freezer, keeping coolers and frozen gel packs on hand, and freezing water in plastic bottles to fill empty freezer space and use as ice.

The 'Danger Zone' is the temperature range between 40°F (4°C) and 140°F (60°C). Bacteria multiply rapidly in this range, so food should not be left in this temperature for prolonged periods.

No, you should never taste food or rely on its appearance or smell to determine its safety. Bacteria that cause foodborne illness can be present without noticeable changes to the food. When in doubt, throw it out.