Boise's winters are cold and variable, with temperatures often dropping below freezing in January and February, but occasionally rising into the mid-teens. As spring arrives, temperatures gradually warm up, with March and April experiencing mild highs in the mid-20s to low 30s Celsius. Summer months bring hot days, particularly in June and July, when temperatures can soar above 40 degrees Celsius, while August is slightly cooler. Autumn sees a return to milder conditions, with September being the hottest month of the season before temperatures drop again in October and November. Winters return by December, mirroring the chilly conditions seen at the start of the year.