Boulder's winters are cold and snowy, with temperatures often below freezing and occasional extreme lows around -29C in February. As spring approaches, temperatures gradually warm up, with April marking a significant increase, averaging 2C. Summer brings warm to hot conditions, with June and July being the warmest months, averaging highs above 15C. Autumn is mild, with September and October experiencing cooler temperatures, before dropping again into winter's chill. The temperature extremes are relatively consistent throughout the year, with occasional spikes into warmer or colder ranges.