Bandelier National Monument protects over 33,000 acres of rugged canyon and mesa country as well as evidence of a human presence here going back over 11,000 years. Petroglyphs, dwellings carved into the soft rock cliffs, and standing masonry walls reflect the early days of a culture that still survives in the surrounding communities. Spring daytime temperatures in the 70's can be followed by a snow storm with wet heavy snow and daytime temperatures in the 40's. Summer is dry, with June usually the hottest month of the year. Days in July, August, and September often end with thunderstorms that can drop heavy localized rain and are often accompanied by lightning. Autumn is usually sunny with turquoise blue skies and warm but not hot days and cool nights. Winter average snowfall is 25 inches, and snow and ice can close trails and roads.