That apple you just ate is probably 5 months to nearly a year old. In the US apples are harvested from August to November. Apples that will sell by December go into regular refrigeration. These giant warehouses are kept at 34-38 degrees. Apples that will be sold later go to controlled atmosphere storage. They're stored at lower temperatures and oxygen levels. Oxygen levels are lowered to 2% (normal oxygen levels are around 21%).
But don't panic, Alisha Albinder a fourth-generation fruit grower says, "If it's handled and stored properly then it should taste the same as when it went in." Apples will lose a bit of acid in storage, but not much changes in its nutritional content.