Final answer:
The clothes froze solid due to the temperature dropping below 0 degrees C overnight. However, instead of melting into liquid water when the temperature increased, the ice directly turned into gas through sublimation, leaving the clothes dry.
Step-by-step explanation:
The clothes were frozen solid because the temperature dropped below 0 degrees C overnight. This caused the water in the clothes to freeze and turn into solid ice.
However, instead of melting into liquid water when the temperature increased during the day, the ice directly turned into gas through a process called sublimation. This means that the ice skipped the liquid stage and went from solid directly to gas, leaving the clothes dry.