Marine layer humidity and your home

The marine layer is part of coastal life. Indoors, it can mean damp closets, musty corners and condensation on windows, especially in rooms with little airflow.

The target

The EPA recommends keeping indoor humidity below 60 percent, ideally between 30 and 50 percent. An inexpensive hygrometer shows where you stand.

Habits that help

• Run bath and kitchen fans during and after use.
• Leave a gap between furniture and exterior walls.
• Do not pack closets tight on exterior walls.
• Use a dehumidifier in damp rooms on humid days.
• Ventilate on dry, sunny days.
• Wipe condensation from windows.

When it is more than humidity

If one spot stays damp or smells musty, look for a leak. See the decision tree.

Sources, accessed Oct 16 to 17, 2026: EPA: A brief guide to mold, moisture and your home · EPA: Mold cleanup in your home