Winters in Mulhouse are cold and variable, with temperatures often below freezing but occasionally rising into double digits. Spring brings a gradual warming trend, with March and April temperatures averaging around 6-8°C, and May being significantly warmer. Summers are mild to warm, with July and August typically seeing highs of around 29-31°C, although overnight lows can still drop to near 10°C. Autumn is marked by a return to cooler temperatures, with September and October experiencing average highs of around 16-18°C before dropping again in November and December. The coldest months are usually January and December, while May is generally the warmest.