Question: How long can milk be left out of the fridge before it becomes unsafe to drink?
Answer: Milk can sit out unrefrigerated for about two hours — or one hour if the temperature is above 90 degrees Fahrenheit — says the U.S. Food and Drug Administration.
The reason is that bacteria grow rapidly when milk is left out at temperatures between 40° F and 140° F. And when it comes to both safety and freshness, milk is vulnerable to changes in temperature.
At home, always try to refrigerate milk as soon as possible after you’ve finished using it. And it’s important to be especially mindful of the time when you've got milk sitting in a hot car after a trip to the grocery store, or on the table at an outdoor meal on a hot day.
Milk that has been properly stored will generally remain drinkable for about one week after the "sell-by" date on the package. Keeping your milk continuously refrigerated will help to keep it fresh as long as possible.