What you're probably noticing right now
If you own a condo along Marina del Rey's waterfront, you've likely already felt the change. The marine layer is thicker in the mornings, the air coming off the channel has that heavier, salt-damp quality, and condensation is showing up on sliding glass doors that stayed dry all summer. Maybe there's a musty smell near a baseboard or a closet that backs onto an exterior wall. None of that is unusual for this time of year. But it's worth paying attention to, because what starts as a damp smell in November can turn into a real mold problem by February, right when the winter storms are pushing moisture into places it doesn't usually go.
Why waterfront buildings here are different
Most of the condo stock around the Marina, from the towers on Via Marina to the lower-rise buildings near Bali Way and Palawan Way, was built between the late 1960s and the 1980s. That generation of construction wasn't designed with today's understanding of vapor barriers or ventilation in mind, and many units sit a few feet above the waterline with underground or semi-subterranean parking that stays damp year-round. Add to that the simple fact that these buildings are surrounded on three sides by water, and you've got a structure that's absorbing moisture from the air constantly, not just when it rains.
Stucco and older window seals, common throughout the complex, don't hold up the same way inland. Salt air degrades caulking and sealant faster than fresh air does, so a window that sealed fine five years ago may now be letting in moisture every time wind drives rain sideways off the channel, which it does regularly during Pacific storms.
More on this from Reading List What A Waterfront Condo Owner Should Check Before The Winter Storms.
What a Pacific storm actually does to these units
Winter storms here don't usually mean prolonged soaking rain like you'd get further north. They mean short, intense systems with strong onshore wind, and that wind is the real issue. It pushes water into gaps around balcony doors, through roof penetrations, and into the stack vents and dryer vents that run through shared walls in many of these buildings. Because units are often stacked with common plumbing chases, a leak two floors up can show up as a stain or a smell in your unit without an obvious source.
Flat or low-slope roofs, common on the boxier 1970s buildings near the marina, are especially prone to ponding during back-to-back storms. Water sits longer than it should, finds a seam, and works its way down into insulation and drywall where it's slow to dry because the surrounding air is already humid.
What you can check yourself before the storms hit
Start outside. Walk your balcony or patio and look at where it meets the building. Caulking that's cracked, pulled away, or chalky should get resealed before the rain starts. Check the weep holes at the bottom of sliding doors and window frames, they're easy to miss and often clogged with salt residue or debris, which stops water from draining out the way it's supposed to.
Inside, open closets and cabinets on exterior walls and give them a sniff and a look. Musty smell, dark spotting, or a slightly soft feel to drywall are early signs worth noting. Check under sinks and around any shared plumbing walls for staining. If you have a dehumidifier, now is the time to run it in rooms that tend to stay humid, particularly ground-floor or garage-level units.
Look at your HVAC or exhaust fans in bathrooms. If they're not pulling air out effectively, humidity builds up indoors even without a leak. A simple test is holding a tissue near the vent while the fan runs, if it barely moves, the fan isn't doing its job.
Where this stops being a DIY job
If you can see mold, you don't need a test to tell you it's there, you need it removed properly, and that's not a homeowner task once it's beyond a small, contained spot you can wipe down yourself. The bigger issue is what you can't see. A smell without a visible source, a stain that keeps reappearing after you've cleaned it, or any history of water intrusion from a past storm season are all reasons to have the air and the wall cavities actually tested rather than guessed at.
This matters more in a building like yours because shared walls and shared ventilation systems mean mold in one unit doesn't always stay in one unit. Testing before the winter storms, rather than after, gives you a baseline. If something does show up after a storm, you'll know whether it's new or whether it was already there. That distinction matters for your HOA, your insurance, and frankly for your own peace of mind going into a season that, around here, tends to bring a few serious storms packed into a short stretch of weeks rather than steady rain spread evenly across winter.