Yellowstone National Park is at high altitude. Most of the park is above 7,500 feet (2,275 meters).

Yellowstone's weather is unpredictable. In summer, it may be warm and sunny with temperatures in the high 70s. At night in any given month, the temperature may drop close to freezing. So it is best to come prepared for cold evenings and mornings, especially if you are camping or hiking. When you leave your campsite, please leave it prepared for possible thundershowers and wind.

A sunny warm day may become fiercely stormy with wind, rain, sleet and sometimes snow. Without adequate clothing and gear, an easy day hike or boat trip can turn into a battle for survival. Exposure to wind, rain, or cold can result in hypothermia. Be prepared! Seasonal Weather Information Spring

Cold and snow linger into May, although temperatures gradually climb. Early in spring, daytime temperatures average in the 40s to 50s; by late May and June, they may reach the 60s and 70s. Nighttime lows fall below freezing.

Summer

Daytime temperatures are usually in the 70s, occasionally reaching the 80s in the lower elevations. Nights are cool, temperatures may drop in the 40s and 30s--sometimes even the 20s. June can be cool and rainy; July and August tend to be somewhat drier, although afternoon thundershowers are common.

Fall

Weather can be pleasant, although temperatures average 10-20 degrees lower than summer readings. Nighttime lows can fall into the teens and lower. Snowstorms increase in frequency and intensity as the weeks go by or towards the end of the fall season.

Winter

Temperatures often hover near zero throughout the day, occasionally reaching highs in the 20s. Subzero nighttime lows are common. Annual snowfall averages nearly 150 inches in most of the park. At higher elevations, 200-400 inches of snow have been recorded.