Takeoff and landing distances are based on surface conditions, and those conditions have to be known for pilots to make accurate decisions for the type of aircr

Takeoff and landing distances are based on surface conditions, and those conditions have to be known for pilots to make accurate decisions for the type of aircraft they are flying. Presumably unexpected water on the runway (which might later freeze, too) would cause the state to deviate from what was expected. For a particular plane, there are some runways that are long enough for takeoff when dry, but not (say) safe for takeoff with water/ice because you cannot abort safely. This is less of a thing for planes flying back and forth between large commercial hubs (since those same aircraft fly every day, in whatever conditions, they are generally sized accordingly). For a military heavy-lift transport, though, this becomes more of a thing.