The park is always open and may be visited anytime of year. Visitation increases as temperatures moderate in the fall, peaks during spring wildflower season, and diminishes during the heat of summer. Joshua Tree Visitor Center Open All Year; 8 am to 5 pm Located one block south of Hwy 62 (Twentynine Palms Highway) at 6554 Park Boulevard, Joshua Tree, CA 92256. Oasis Visitor Center Open All Year; 8 am to 5 pm Located at park headquarters: 74485 National Park Drive, Twentynine Palms, CA 92277, at the junction of Utah Trail and National Park Drive. Cottonwood Visitor Center Open All Year; 8 am to 4 pm Located eight miles north of Interstate 10 at Cottonwood Spring. Black Rock Nature Center Open October through May 8 am to 4 pm except on Friday; Noon to 8 pm on Friday Located at 9800 Black Rock Canyon Road, Yucca Valley, CA 92284, in Black Rock Campground. Weather and Climate Days are typically clear with less than 25 precent humidity. Temperatures are most comfortable in the spring and fall, with an average high/low of 85 and 50°F (29 and 10°C) respectively. Winter brings cooler days, around 60°F (15°C), and freezing nights. It occasionally snows at higher elevations. Summers are hot, over 100°F (38°C) during the day and not cooling much below 75°F (24°C) until the early hours of the morning. Average Monthly Temperature and Precipitation Weather Forecast The National Weather Service forecast for Joshua Tree National Park.