Weight

• Pick up the orange you are considering purchasing. Observe its weight in your hand. Pick up another orange of a similar size to compare their weights. A healthy, juicy orange will be relatively heavy for its size; a comparatively light weight indicates that the orange is fairly dry inside. If you are not familiar with the typical weight of oranges -- and therefore are unable to immediately assess whether one is relatively heavy or light -- perform the test somewhere with an abundance of oranges so you can compare their weights and select the heaviest ones.
  
  

Feel

• A ripe, healthy orange should feel firm, without any squishy or overly soft parts. It should not be rock-hard, however, and should give slightly under gentle pressure. When you rub your thumb or fingers over the orange's peel, it should feel relatively smooth. Different varieties of oranges have different acceptable levels of smoothness, however, those that are naturally bumpy or lumpy should be comparatively smooth for that variety -- not smooth compared to another type of orange.
  
  

Signs of Damage

• Do not purchase oranges that have obvious signs of damage or decay. One of the most noticeable of these is mold, which typically appears as a powdery white substance on oranges. Other external signs that the orange is damaged include visible bruises, cracks or splits in the peel or splotches of discoloration. You should also avoid any orange that has a wrinkled or shriveled peel or otherwise appears to be past its prime.
  
  

False Indicators

• Some signs that seem like they should provide information about an orange's condition and ripeness actually do not. A perfectly ripe orange can still be partially green; some bright orange oranges are actually dyed that color. Do not, however, purchase oranges that are otherwise discolored. Size also provides little to no indication of ripeness, as some varieties of oranges are naturally very small while others tend to be quite large.