How to Clean Mold From Windowsills

A gray cat sitting next to a window
Warmer weather brings myriad joys into our lives, including throwing open the windows to let in some fresh air.

But wait! Is that mold on your windowsills? Ewww. Moldy windowsills are unsightly and not good for the overall health of your home as they could lead to bigger problems. Rest assured, we’re here to help with step-by-step instructions for how to remove mold from windowsills!

Keep reading to learn Molly Maid’s tips for how to clean mold from windowsills …

What to Use to Clean Mold From Windowsills

While many cleaning solutions will work to remove some mold, using the right solution can help ensure the mold spores are being killed, preventing the mold from starting to grow back after you finish cleaning.

We recommend using one of these two options:

Bleach Water: Use a mixture of warm water and chlorine bleach. We recommend following the directions of the bleach manufacturer to know how much bleach and water to mix together.

White Vinegar & Water: If you prefer to not use bleach, you can also try a solution of equal parts white vinegar and water.

How to Remove Mold From Windowsills

Before you get started, consider wearing a dust mask and rubber gloves to limit your exposure to the mold. Then, follow these steps:

  1. Wet a toothbrush with the cleaning solution of your choice. Scrub the area with some elbow grease to break up the mold particles.
  2. Once the mold has been scrubbed, use a damp microfiber cloth to wipe the surface clean.
  3. If more mold remains, repeat the process until it has been removed.

Keep Mold at Bay

As we mentioned above, mold can come back. Using a cleaning solution that kills mold will help, but if the conditions that made the windowsill moldy to begin with remain, the mold is likely to return. Check your windows for leaks, moisture on the windowpanes, or other issues that could be providing a moist environment for mold to grow.

Fixing the moldy windowsill issue at the root cause will better prevent mold in the future, as opposed to regularly cleaning it.

Let Someone Else Clean the House

While you’re busy taking care of things around the house, why not let someone else tackle the everyday cleaning? Molly Maid offers customized cleaning plans to fit your budget and schedule. Request a free estimate online. One of our locally owned cleaning service locations would be happy to help!


If you’re looking to fix or replace your windows, Glass Doctor® offers reliable window services. Glass Doctor is a fellow member of the trusted Neighborly® network of home service brands.