What a Very Strong El Nino Means for San Diego Landlords This Winter

El Nino doesn’t promise a soaked winter. It does tilt the chances toward one, and wet winters find the weak spots in older rental buildings fast.

Owners who come through these seasons in good shape tend to fix roofs and drainage early, know what California law expects, and line up help before they need it.

That last step matters more than it sounds. With a 24/7 IICRC-certified firm like Pacific Flood Restoration of San Diego on call, drying can start while you handle tenants and paperwork.

What the Forecast Actually Says

The Climate Prediction Center’s September 2026 El Nino discussion gave a very strong event with better than 90% chances for fall and winter.

It also gave a 75% chance that, from October through December, this event outpaces every El Nino on record since 1950.

Strong El Nino years have a mixed record here. A County of San Diego briefing on the 2026-27 outlook lists widespread flooding, road closures, mudslides and sinkholes from the 1997-98 event.

The 2015-16 El Nino was also big, but the storm track mostly missed California. The County’s summary says a wetter winter is favored, though forecast confidence is limited.

One storm can do the damage on its own. On January 22, 2024, San Diego’s airport station recorded 2.73 inches of rain, the wettest January day in its records.

So plan around the chances, not a promise.

Where Rental Units Usually Take Water First

Stormwater tends to enter rentals through the same handful of places. Checking them in October costs far less than drying them out in January.

• Roofs and flashing. Low-slope roofs on older apartment buildings can pond water, and cracked flashing around vents and skylights lets it through.

• Gutters and downspouts. A downspout that empties beside the foundation sends water toward ground-floor units and slabs.

• Windows and sliders. Clogged weep holes in sliding door tracks push water onto the floor during wind-driven rain.

• Stucco and wall penetrations. Water slips behind stucco at hose bibs, light fixtures, and cable entries long before a stain appears.

• Low spots on the lot. Driveways that slope toward garages, below-grade units, and patios with blocked drains collect runoff.

• Sewer lines. Heavy rain can overload sewer systems and push contaminated water back up through floor drains and toilets.

Walk the property after the first light rain of the season. Damp spots that appear after a small storm only get worse in a big one.

What California Law Expects From Landlords

Civil Code 1941.1 lists what makes a rental habitable. First on that list is effective waterproofing and weather protection of the roof and exterior walls, including unbroken windows and doors.

The same section requires plumbing to be kept in good working order. A roof that leaks every time it rains falls short of that standard.

Mold is covered too. Health and Safety Code 17920.3 lists visible mold growth, as determined by a health or code enforcement officer, among the conditions that can make a building substandard.

Minor mold on surfaces built to handle moisture, such as a shower, is excluded. Mold spreading across drywall after a storm leak gets no such exception.

Entry rules still apply during storms, with a clear carve-out. Civil Code 1954 presumes 24 hours’ written notice is reasonable and allows entry without notice in case of emergency.

If you go in during a water emergency, write down when you entered and why.

One more rule catches owners off guard. For leases signed on or after July 1, 2018, Government Code 8589.45 requires a flood hazard disclosure.

Landlords must tell tenants if they know the property sits in a special flood hazard area or an area of potential flooding. The notice also points tenants to the state’s MyHazards tool.

It must also state that the owner’s insurance won’t cover the tenant’s belongings and recommend renters and flood insurance. If your lease template predates 2018, check it this month.

An October Checklist Before the First Big Storm

Work through this list while the weather is still dry.

1. Clean gutters, downspouts and roof drains, and extend downspouts away from the building.

2. Have a roofer check flashing, vent seals, and any ponding areas on flat roofs.

3. Clear slider weep holes, patio drains, and the area drains at the base of driveways.

4. Make sure every tenant knows where the main water shutoff is and how to report a leak after hours.

5. Encourage renters insurance, and mention that standard renters policies usually exclude flood. Tenants can buy flood coverage for their belongings through the NFIP.

6. Review your own policy for flood exclusions and loss-of-rent coverage. New NFIP policies usually take 30 days to start, so decide now.

7. Check the City of San Diego and County websites for free sandbag locations, which are usually posted ahead of major storms.
8. Save a 24/7 restoration company’s number in your phone and in your property manager’s notes.
   

When Water Gets In Anyway

Even well-kept buildings take water in a big storm. What happens on the first day often decides whether you’re paying for drying or for mold removal.

The EPA advises drying water-damaged areas and items within 24 to 48 hours to prevent mold growth. Damp coastal air can also slow drying near the beach.

Stop the water source if you safely can, and keep tenants away from standing water near outlets. Photograph every wet wall, floor and damaged item before anything is moved.

Then call your insurer and get extraction and drying started the same day. Update tenants in writing as the work moves along.

If a unit becomes unlivable, check your lease and local rules on rent and temporary housing before making promises. Those answers come easier in October than at midnight in February.

Plan Around the Chances

A very strong El Nino doesn’t guarantee a flood. It is a good reason to fix the roof, update the lease, and line up help while the weather is calm.

Put those three jobs at the top of your October to-do list. The owners who finish them early usually spend the winter fixing small problems instead of big ones.