Get the most current data. Before embarking, investigate the weather forecast, wildfire status, air quality, and any closures in and around your destination. The National Interagency Fire Center (nifc.gov) has maps and up-to-date information on wildfires. Find weather alerts and air-quality information on the National Weather Service website (weather.gov). For more localized information, check helpful websites run by state tourism offices, specific public lands agencies and, often, local gear shops. For instance, Teton Mountaineering’s “Local Resources” section for Jackson Hole in Wyoming links to mountain weather forecasts, Teton County Search and Rescue and Grand Teton National Park (tetonmtn.com). Calling public lands’ visitor centers or local tourism offices can also yield valuable information; national park officials, for example, closely monitor the weather and hone their visitor outreach accordingly. Knowing what you’re apt to encounter will help you decide what to pack (extra water bottles, sunscreen and sun hats, for example) and how ambitious to be with your hiking, biking or climbing plans.