The answer to 'why is my window mildew' is that window mildew is typically caused by excess moisture and poor ventilation. Mildew thrives in damp, humid environments and can grow on windows due to condensation buildup, leaks, or lack of airflow. Symptoms include a fuzzy, discolored growth on the window glass or frame.
To address window mildew, it's important to identify and fix the underlying moisture issue. This may involve improving ventilation, repairing any leaks or cracks, using a dehumidifier, or adjusting the temperature to reduce condensation. For mild cases, you can often clean the mildew yourself using a mixture of water and white vinegar or a commercial mildew remover. However, for more severe or recurring mildew, it's best to call a professional cleaning service to properly treat the problem and prevent future growth.