The answer to 'why is my gutter dusty' is that gutters can become dusty due to a buildup of debris, pollen, and other airborne particles over time. This is a common issue that many homeowners face, especially in areas with a lot of trees or during dry seasons.
Some common causes of dusty gutters include leaves, twigs, and other organic matter that accumulate in the gutters, as well as dust and dirt that gets blown in by the wind. The dust can also come from nearby construction or landscaping activities. Over time, this buildup can make the gutters appear dirty and discolored.