Elevations in the park range from approximately 7,000 feet to 8,182 feet on the crater rim. Windy conditions may exist at the top of the volcano. Summers are mild, with highs in the mid-80s Fahrenheit, and thunderstorms are common in July and August. The top of the volcano closes during thunderstorms. Light jackets may be needed during the summer. Winters are cold, and blizzards may result in temporary closures. Warm and layered clothing should be worn the rest of the year.