In just about any weather short of a full typhoon, day or night, an aircraft carrier can engage in battle. Flight crews and deck personnel train hard for operations in every condition and environment. In modern warfare, you cannot expect the enemy to wait for a nice day. In fact, just the opposite is true: troops will move and attack under the cover of darkness, in bad weather, and without warning. The ability to take the battle to the enemy, in all conditions, is as much an offensive as a defensive advantage.
Night ops are among the most dangerous and frequently practiced. It doesn't take much to understand why -- imagine landing on the pitching deck of an aircraft carrier in the blackness of midnight or launching off the ship into the utter darkness ahead on a moonless night, also called the "night cat shot". The decks are so narrow that a small error can create a collision with the ship's superstructure. Larger planes like the E-2C have a particularly critical problem with less than three feet of clearance to the side. Landing just a touch off centerline will rip off a wing and flood the decks with aviation fuel.