New Mexico is typically sunny year-round, with a mild, semi-arid climate. Summer monsoons bring relief with sudden, but brief afternoon rainstorms. Lightning is common on park grounds. Fort Union is situated at 6,760 feet above sea level. Daytime temperatures between June and September may exceed 90 degrees Fahrenheit. Winter temperatures often drop below 32 degrees Fahrenheit. Temperatures may vary within 50 degrees in a 24-hour period.
During the winter, it is not uncommon for the temperatures to dropbelow 0°F (-18°C). Hypothermia is a hazard
during the winter season. in late fall, winter and early spring.
During the summer, expect high temperatures, intense sunlight and low humidity. Eat plenty of food and drink at least one gallon of water each day. Carry and drink water during all activities, such as hiking. Wear loose-fitting, light-colored clothing and a wide-brimmed hat. Apply sunscreen to all exposed skin. Consider saving strenuous activity for early mornings or evenings. Water is available at the visitor center.
Sun umbrellas for loan and water fountains are available at the Visitor Center.
A covered picnic shelter is available adjacent to the visitor center.
Multiple benches are located throughout the monument grounds on the walking trail.