Relative humidity can create mold-friendly conditions even when there’s no obvious plumbing leak or water intrusion. In North Carolina homes, high outdoor humidity, HVAC problems, condensation, crawl spaces, basements, and other moisture sources can all influence what’s happening indoors. In this guide, Mold Patrol co-owner Brian Murphy explains what humidity readings homeowners should watch, why prolonged high humidity matters, and what Mold Patrol found in a home measuring roughly 74–78% relative humidity. You’ll also learn how HVAC condensate problems can raise indoor moisture, why a dehumidifier isn’t always the complete solution, and when persistent humidity deserves a closer investigation.