When will ski resorts in Sierra Nevada open for the ski season? The 2025/26 Sierra Nevada Ski season starts from 2025/11/21. See this list of projected opening dates for Sierra Nevada mountains. Important Note: Not all dates listed here are official and final, as resort opening dates are projected and subject to change. Check back for updates on when the lifts are set to start spinning at Sierra Nevada, and don't miss opening day at your favorite resort!