Desert weather can change swiftly and dramatically. Knowing the forecast is an important part of preparing for your Joshua Tree visit. The National Weather Service forecast for Joshua Tree National Park is a good starting point. Note that this forecast zone covers a vast area with elevations ranging from 536 feet (163 m) in the park's extreme southeast corner to 5,814 feet (1,773 m) atop Quail Mountain. Conditions may vary greatly depending on your exact location within the park. Remember, your safety is your responsibility. Basic Information - Joshua Tree National Park (U.S. National Park Service)