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Prevention Strategies

Permanent Shade

Two types of permanent shade are trees and built structures. Both can protect your skin from the sun's ultraviolet (UV) rays.

When planning your outdoor activities, it is a good idea to think about where you can find shade throughout the day. If you know that there will not be any shaded areas where you are going, be sure to bring your own!


Trees can be an excellent source of shade - dense trees screen out about 80% of the sun's UV rays. For the best shade, look for trees with thick canopies, large leaves, and wide-reaching branches.

Since trees do not block 100% of UVR, be sure to use sunscreen or cover-up clothing for the best protection.

To learn which trees provide the best shade, visit the CSU Extension website.

Permanent Shade Structures

Permanent shade structures such as porches, ramadas, shade cloths and umbrellas, can provide year-round protection. The style of the structure affects the quality of shade beneath it. Structures that use solid wood, metal roofing, or a shade cloth screen out at least 95% of UV light.

Fabric-based shade structures are common and provide varying degrees of sun protection.The two primary factors that affect the sun protective quality of fabrics used in shade products are weave and color:

  • Fabrics with a tight weave block more sunlight than loosely woven fabrics. Fewer, smaller holes between the threads allow less UVR to pass through to the skin.
  • Darker colors of fabrics absorb UVR better than lighter colors. Lighter colors reflect infrared light, which feels cooler, but they are less protective against UV light.