Winter was a season on Earth, notably for usually being cold.
River Song was taken by the Doctor for her birthday to the last Winter Frost fair on the River Thames in 1814. Stevie Wonder unknowingly performed before being taken back to his original time. (TV: A Good Man Goes to War)
During World War II, winter in Russia brought the forces of Nazi Germany to a halt after they invaded the Soviet Union in 1941. The Red Army used the opportunity to counterattack, driving the Germans back from Moscow. (PROSE: Just War) Winter arrived again in late 1942 after the Germans began their attack on Stalingrad. Many Russian civilians froze to death. (PROSE: The Beast of Stalingrad)