hot desert climate (Köppen climate classification: BWh), typical of the Mojave Desert in which it lies. This climate is typified by long, extremely hot summers; warm transitional seasons; and short winters with mild days and cool nights. There is abundant sunshine throughout the year, with an average of 310 sunny days and bright sunshine during 86% of all daylight hours. Rainfall is scarce, with an average of dispersed between roughly 26 total rainy days per year. Las Vegas is among the sunniest, driest, and least humid locations in North America, with exceptionally low dew points and humidity that sometimes remains below 10%. The summer months of June through September are extremely hot, though moderated by extremely low humidity. July is the hottest month, with an average daytime high of . On average, 137 days per year reach or exceed , of which 78 days reach and 10 days reach . During the peak intensity of summer, overnight lows frequently remain above , and occasionally above . While most summer days are consistently hot, dry, and cloudless, the North American Monsoon sporadically interrupts this pattern and brings more cloud cover, thunderstorms, lightning, increased humidity, and brief spells of heavy rain. Potential monsoons affect Las Vegas between July and August. Summer in Las Vegas is marked by a significant diurnal temperature variation. While less extreme than other parts of the state, nighttime lows in Las Vegas are often or more lower than daytime highs. The average hottest night of the year is . The all-time record is at . Las Vegas winters are short and generally very mild, with chilly (but rarely cold) daytime temperatures. Sunshine is abundant in all seasons. December is both the year's coolest and cloudiest month, with an average daytime high of and sunshine occurring during 78% of its daylight hours. Winter evenings are defined by clear skies and swift drops in temperature after sunset, with overnight minima averaging around in December and January. Owing to its elevation that ranges from , Las Vegas experiences markedly cooler winters than other areas of the Mojave Desert and the adjacent Sonoran Desert that are closer to sea level. The city records freezing temperatures an average of 10 nights per winter. It is exceptionally rare for temperatures to reach or fall below . Most of the annual precipitation falls during the winter months. February, the wettest month, averages only four days