Winters in Waltham are typically cold, with temperatures often below freezing, and average lows around -2°C in January and December. Spring brings a gradual warming trend, with March averaging 4°C and April reaching an average high of 25°C. Summers are warm to hot, with July and August experiencing average highs near 33°C, while September and October see a return to more moderate temperatures. Falls are generally mild, with November's average temperature ranging from -5°C to 21°C, before the cold winter weather returns in December. Overall, Waltham's temperature fluctuations are pronounced throughout the year, but the region experiences a distinct change of seasons.