Winters in Gelsenkirchen are cool and unpredictable, with January averaging around 3°C and temperatures sometimes dropping as low as -15°C. Spring brings gradual warming, with March and April temperatures rising steadily to an average of 6-7°C. Summers are mild, with July being the warmest month at 18°C on average, but still relatively cool compared to other parts of Europe. Autumns are also quite pleasant, with September averaging around 16°C, before cooling down again in October and November. The coldest months are December, January, and February, while the warmest months are June, July, and August.