Find a trusted weather forecast for the day or evening of the outdoor concert. When your outdoor concert is a rain-or-shine event and rain is in the forecast, bring a poncho or rain slicker.
Pay attention to the heat index and relative humidity as well as the temperature. High levels of humidity make the day seem hotter than the temperature alone indicates. Compensate by drinking more water.
Keep your skin covered to prevent excessive sun damage at an outdoor concert that takes place during the day. Choose light-colored, loose-fitting clothing.
Add a hat to keep the sun off your sensitive scalp. Hats also block the sun's glare so you can see the performers on stage.
Wear comfortable walking shoes. Outdoor concerts are equal parts standing and walking, and you may be on your feet all day.