Summer heat doesn’t just stick to the forecast—it works its way into corners, under surfaces, and behind walls. While you’re out soaking up the season, your house could be collecting moisture in all the wrong places. Closed-up rooms and slow-moving air turn into a welcome mat for mold. It only takes a little trapped humidity before it starts multiplying in places you weren’t even thinking about.
Here are the top 5 places mold loves to grow in the summer in your Denver home and how to stop it.
#1 Inside Your AC
Your air conditioner is working overtime, but it might also be harboring moisture you never see. The drip pan underneath your unit catches condensation all day long, and in that dark, damp space, mold settles in without much resistance. Peek under the hood every couple of weeks. If the pan looks grimy or feels slimy, clean it out and double-check that the drain isn’t blocked. A tiny bit of standing water is all it takes to start a full mold patch. If you’re not already using a treatment tab or strip in the tray, it might be time to start.#2 Window Tracks
A quick storm rolls through, your windows fog up, and then things dry out—or so it seems. What happens is that moisture sneaks into the track and sits there. Give it a few days and you’ll spot the black dusting along the edges. Use a toothbrush or detailing brush to sweep those tracks clean, especially after a humid spell. If your windows stay shut most of the summer, give them some fresh air now and then. Stillness and moisture are the combination that mold likes most.#3 Behind Your Couch
That one spot behind the couch or dresser against an exterior wall? It’s a perfect target. The airflow back there is nonexistent, and summer sun hitting the outside of the wall can crank up the temperature just enough to create a pocket of humidity. Shift your furniture out a few inches. It doesn’t have to be dramatic, but enough to let the air move and the wall breathe. If it’s already damp, run a fan near the spot or leave it exposed for a bit and check back later.#4 Under the Kitchen Sink
There’s something about the cabinet under the sink that invites clutter, forgotten drips, and mold. You might not see a leak, but a slow, steady drip from a loose fitting can soak the back corner until mold has its zip code. Clear everything out and run your hand along the back wall and around the pipes. If it feels cool and damp, dry it out with a towel and leave the cabinet open to air out. You don’t need a major leak for mold to move in, just a lazy one that goes unchecked.#5 Laundry Machines That Never Get to Breathe
Your washer gets cleaned, but the gasket around the door, especially on front-load machines, is a mold magnet. It stays warm, damp, and rarely gets wiped down. That rubber seal holds onto water like it’s trying to win a contest. After a load, crack the door open and let the drum dry. Wipe the seal out with a rag now and then, especially if you notice any odor creeping into your laundry. If it already smells funky, a vinegar rinse and a bit of scrubbing will clear out most of what’s hiding in the folds.Bonus Spot: Your Bathroom Exhaust Fan
Your exhaust fan helps remove steam after a shower, but it can also collect moisture in its housing and ductwork, especially if it’s not used regularly or left running long enough. Over time, that trapped moisture can lead to mold buildup you can’t see. Make sure your fan is running for at least 20 minutes after each shower. If possible, install a timer switch or humidity sensor. Every few months, remove the cover and gently clean the fan blades and the surrounding area.Prevention Tips That Go a Long Way
- Use a dehumidifier in high-moisture areas, especially basements and bathrooms.
- Improve ventilation by running fans or cracking windows, even just for a few minutes each day.
- Fix leaks fast and don’t ignore musty smells—they’re often the first sign of hidden mold.
- Keep humidity under 60% indoors. If you don’t have a hygrometer, it might be time to get one.
