Oberhausen's winters are cold and variable, with temperatures often below freezing in January and December, but occasionally rising into double digits. Spring arrives slowly, with March and April bringing mild days and occasional warm spells, but still quite cool at night. Summer is a pleasant time, with June and July seeing highs often above 25C, though the temperature drops significantly overnight. Autumn brings a return to cooler temperatures, with September and October experiencing some chilly mornings, but overall remaining relatively mild. The coldest months tend to be January and December, while the warmest are typically June and July.