Winters in Broomfield are cold, with temperatures often below freezing and averaging around 0°C in January. February is similarly chilly, with averages dipping as low as -3°C. Milder temperatures return by March, with averages rising to 4°C, marking the beginning of spring. As spring progresses into summer, temperatures steadily warm up, peaking in June and July with averages around 22-24°C. Autumn brings a gradual cooling trend, with temperatures dropping back down to near-freezing levels by November.