Upper Darby experiences a cold and variable winter, with temperatures ranging from -15°C in February to mild days around 13°C in January. As spring arrives, temperatures gradually warm up, with March averaging 7°C and April reaching highs of 30°C. Summer months bring warmer temperatures, with July and August averaging around 24°C, but temperatures can still drop to as low as 14°C on cooler days. Autumn brings a return to cooler temperatures, with September experiencing mild days around 8°C before dropping to around 3°C in October. Winters are generally quite cold, with temperatures ranging from -9°C to 19°C throughout the season.