Long term, direct sunlight will permanently fade the dyes used in your oriental rug. If direct sunlight cannot be helped, rotate your rug frequently or consider a window tint or shades to limit sunlight. Sunlight is most damaging when air humidity is low. In Texas, because our humidity is relatively high, the most damage to rugs is in early spring and early winter. In Utah and Arizona, for instance, sunlight will be must more damaging to a rug than in Texas. Just remember to regularly rotate those rugs in heavy sunlight areas.