Deep dive · Updated October 17, 2026

El Niño roof prep for Marin homes: a 2026–27 checklist

The roof is the first part of your home that every storm hits. This guide is roof-only. For the full household checklist (sandbags, alerts, go-kits, flood zones), see North Bay Pros' Marin El Niño storm-prep guide. If you want the pro-inspection side (roof age, materials, solar, fire ratings), read our El Niño roof prep checklist; this page focuses on what you can check yourself and what to do when a leak starts.

Why roofs matter more this winter

As of the NOAA Climate Prediction Center's ENSO Diagnostic Discussion issued October 8, 2026, an El Niño Advisory is in effect. CPC says El Niño "continues to strengthen," with a strong-to-very strong event likely through January–March 2027 (greater than an 83% chance), and the Niño-3.4 index reached +2.1°C last month. CPC also stresses that with an event this strong, the chances of typical El Niño impacts are "larger, though not guaranteed." In other words: a wet winter is more likely, not certain. The next CPC update is scheduled for November 12, 2026.

A season of repeated, wind-driven storms finds weak spots that a normal winter might not. The goal of the steps below is to find those weak spots while it's dry and roofers have open schedules.

A ground-level roof inspection you can do safely

You don't need to climb a ladder to learn a lot. Walk around the house with binoculars on a clear day and look for:

• Missing, cracked, curled or lifted shingles, especially on the windward side and along ridges and edges
• Bare spots or heavy granule loss on asphalt shingles (granules often collect at downspout outlets)
• Loose or rusted flashing around chimneys, skylights, vents and where a roof meets a wall
• Sagging rooflines or dips that could mean a deck problem
• Moss and debris piles in valleys and behind chimneys, which hold water against the roof
• Damaged or popped vent boots around plumbing pipes

Stay off a wet, steep or tile roof. If you aren't comfortable on a ladder, leave it to a pro.

Check the attic from the inside

On a dry afternoon, take a flashlight into the attic and look for:

• Daylight through the roof deck (other than at designed vents)
• Dark stains or rings on rafters and the underside of the deck
• Damp, matted or discolored insulation
• Rusty nail tips, which can be a sign of condensation rather than a leak

Take photos of anything you find so you can compare after the first storm. If you're unsure whether you're seeing a leak or condensation, our article on roof leak vs. attic condensation explains the difference.

Gutters, downspouts and drip edge

Clogged gutters overflow behind the fascia and into walls, and they let water sit against the roof edge.

• Clean gutters after the leaves drop, and again mid-winter if you have oaks, pines or redwoods overhead.
• Make sure gutters slope toward downspouts and that hangers are tight.
• Confirm each downspout carries water away from the foundation. Marin sanitary districts prohibit connecting downspouts to the sewer.
• Look for a drip edge along the eaves; missing or bent drip edge lets water wick under shingles.

Flashing and penetrations: where most leaks start

Leaks rarely come through the middle of a sound roof. They start where something interrupts it: chimneys, skylights, vents, satellite mounts, solar standoffs and wall intersections. Before the season, ask a roofer to check:

• Step and counter-flashing at chimneys and walls
• Skylight curbs and seals
• Pipe boots and vent collars
• Sealant that has cracked or pulled away (sealant is a short-term fix, not a substitute for proper flashing)

Trees and the roof

Overhanging limbs scrape shingles, drop debris into valleys and can come down in high winds on saturated soil. Have an arborist assess large limbs over the house, and never trim near power lines yourself.

Emergency tarping: what it is and who should do it

A properly installed tarp can protect a damaged roof until a permanent repair. Doing it right means working on a slick, often steep surface, securing the tarp over the ridge and fastening it so wind can't get under it. That's a job for a licensed roofer, not a homeowner in a storm. Our emergency tarping service page explains what to expect.

Roof leak triage during a storm

1. Catch the drip with a bucket and move furniture and electronics away.
2. If a ceiling is bulging with water, keep everyone out from under it and call for help. Don't stand under it to poke it.
3. Note what's happening: heavy rain only, wind from one direction, constant drip. These clues help a roofer find the source.
4. Photograph the leak, the ceiling and any damage for your insurer.
5. Stay off the roof until the storm passes.

If water is soaking walls, floors or insulation, the clock on drying starts now. The EPA says to dry water-damaged areas within 24–48 hours to prevent mold. See our water damage site's guide for the first hours after water gets in.

When to call a roofer

• You see missing shingles, lifted flashing or damage from the ground
• There are stains in the attic or on ceilings
• A leak comes back after a storm, even if it stopped
• Tree limbs hit the roof
• Your roof is near the end of its life and you want a pre-season assessment

Always check a roofer's license with CSLB before hiring, and be wary of anyone who knocks on doors right after a storm.

Sources

• NOAA Climate Prediction Center, ENSO Diagnostic Discussion, Oct 8, 2026
• U.S. EPA, A Brief Guide to Mold, Moisture and Your Home
• San Rafael Sanitation District, Sewer Laterals
• Contractors State License Board, Check a License
• North Bay Pros, Marin El Niño storm-prep guide

Frequently asked questions

This guide is general information, not legal, insurance or medical advice. Sources are linked in the text. Marin Roof Repair is a referral service and doesn't perform the work.