It seems that opinion varies quite a bit when it comes to whether you should be storing your Mandarin oranges in the refrigerator or if you want to leave them out at room temperature on the counter or in a cupboard. But how should you really be storing them?
The first question is how long you need the oranges to last for. If your family is going to finish the box of Mandarin oranges within a week, then you want to leave it out at room temperature. You can put them in the pantry if you are storing them in a plastic bag, but if you are keeping them in the box that most mandarins come in, you can leave them on the counter.
Storing Mandarin oranges at room temperature is considered the ideal way to store any citrus fruit. And the biggest reason why your oranges will go bad is if you happen to get one moldy mandarin orange in the box, and it can quickly spread to others. So every day you should check through the box of oranges, and make sure none are starting to go bad.
However, if you are not going to finish an entire box of oranges within the week, then you probably want to think about putting them in the fridge before the week is up. When they are in the fridge the Mandarin oranges are going to last for 2 to 3 weeks, and sometimes longer. So you want them in the fridge if you are going to not eat them very quickly. But you do also want to check your oranges every couple of days also to make sure that no oranges have gone bad.