Winters in Union are cold and variable, with temperatures fluctuating between -20°C and 6°C on average. March marks the beginning of a slow warming trend, as daytime highs reach up to 25°C while nighttime lows dip to around -16°C. By April, temperatures have risen significantly, averaging 8°C as spring begins to take hold. Summer months from June to August are mild, with average temperatures ranging between 20-22°C, punctuated by occasional heatwaves that push temperatures into the mid-30s. As autumn sets in, September's warmth gives way to a gradual cooling trend, with temperatures dropping back down to around 3°C by November and December.