Rainy Season in Los Angeles: 7 Ways to Prevent Window & Door Leaks Before They Start

In Los Angeles, “rainy season” might not feel like Seattle—but when it hits, it finds every weak spot. If you’ve ever seen water staining near a window corner, felt a door threshold go spongy, or noticed musty smells after a storm, it’s usually not the rain itself—it’s how water is being directed (or not directed) around the opening.

Here are seven practical, homeowner-friendly steps to reduce leak risk before the next storm rolls through LA County.

1. Look for the early warning signs

Catch problems before they become drywall repairs.

• Bubbling paint or soft drywall near corners

• Dark staining on trim or sill areas

• Swollen baseboards near patio doors

• Condensation between panes (a failed seal)

2. Clear and test your weep holes

Many window systems are designed to manage small amounts of water.

• Make sure exterior weep holes aren’t clogged with dirt or paint

• After cleaning, lightly hose-test the area (don’t blast it like a pressure washer)

3. Inspect exterior caulking—especially on the sunny sides

UV exposure in Los Angeles breaks down sealants fast.

• Check for cracking, gaps, or peeling caulk

• Don’t just smear more on top—failed caulk usually needs removal and re-application

4. Check thresholds and sill pans on doors

Patio doors take a beating from foot traffic and pooled water.

• Look for cracked sealant at the bottom corners

• Make sure the threshold isn’t separating from the frame

• Verify track drains aren’t blocked (especially on sliders)

5. Don’t ignore stucco and paint cracks near openings

Hairline cracks can become water pathways.

• Pay attention to cracks radiating from window corners

• If you see recurring cracks, it may point to movement or poor detailing

6. Make sure gutters and downspouts aren’t dumping water onto openings

This one is huge.

• Extend downspouts away from door/window areas

• Keep gutters clear so water doesn’t overflow onto walls

7. If you’re replacing windows/doors, prioritize proper integration

The best leak prevention is correct installation details.

• Proper flashing and waterproofing at the opening

• Correct sill/threshold detailing

• Materials suited for your wall type (stucco, siding, etc.)

Quick FAQ

Do new windows automatically stop leaks?

Not always. Leaks are often an installation or waterproofing-detail problem, not just an old-window problem.

Should I caulk everything?

No—some systems need drainage paths. The goal is controlled water management, not trapping moisture.

Next step

If you’ve noticed staining, drafts, or swelling around windows or doors, it’s worth diagnosing before the next storm. We can take a look, explain what’s happening, and recommend the right fix—whether that’s a repair, re-seal, or a properly integrated replacement.