El Niño gutter prep for Sunnyvale and the Peninsula, before the first storm.

NOAA forecasts a very strong El Niño this winter, likely the strongest since 1997-98. Its Climate Prediction Center has an El Niño Advisory in place, and its October 8 update gives a greater than 83 percent chance of a strong to very strong El Niño through January to March 2027 and an 83 percent chance that October to December becomes the strongest El Niño on record since 1950. For the Bay Area that raises the odds of a wet winter, but El Niño’s pull on rain here is weaker and less reliable than in Southern California.

The Palo Alto gauge recorded 33.59 inches in the 1997-98 season, more than twice its normal year of 15.12 inches, and 12.43 inches of that fell in February 1998, according to NOAA station records. Redwood City got about 37.62 inches against a normal 19.02, and Half Moon Bay 50.69. In the 1982-83 El Niño, Moffett Federal Airfield on the Sunnyvale line got 28.10 inches, about twice its normal year.

Start with a full cleaning and a flush of every downspout, then fix what the water will find: leaking seams and end caps, sagging runs with the wrong slope, and long roof sections draining to a single downspout. Carry the water away from the foundation with extensions or underground drainage, and add BroGuard mesh so debris does not rebuild between storms.

In October or early November, before the first big storm. At Moffett Federal Airfield about 84% of a normal year’s rain falls from November through March. A Solutionist walks the roofline, and the crew does the work the same day whenever possible, with a written report of what was cleaned, fixed and still recommended. Call (650) 600-0598 early.

Because roof water released onto a slope adds to ground that is already saturated. In 1997-98 San Mateo County had about $55 million in landslide damage, and cut-and-fill slopes gave way in residential Portola Valley and San Bruno during the storm of February 2 and 3. Where your downspouts end matters as much as the gutter itself.

Yes, fast. Redwood and pine needles, oak leaves and liquidambar drop can refill an open gutter within weeks, and in a back-to-back storm pattern there is no dry window to get up and clean between systems. Stainless BroGuard micro-mesh keeps the trough clear all season, so the gutter you paid to clean in October still works in February.

NOAA’s October 8, 2026 update keeps an El Niño Advisory in effect and gives a greater than 83% chance of a strong to very strong El Niño through January to March 2027. In the Bay Area that raises the odds of a wet winter but does not guarantee one. The National Weather Service notes there is little correlation between most El Niño patterns and Northern California rain, and in the strong 2015-16 El Niño Moffett Federal Airfield got 13.17 inches, about a normal year. Have the gutters ready either way.

About 13.45 inches at Moffett Federal Airfield on the Sunnyvale and Mountain View line, based on NOAA’s 1991-2020 normals, and about 84% of it falls from November through March, with February the wettest month at 2.90 inches. Palo Alto averages 15.12 inches, Redwood City 19.02, and the Skyline Ridge Preserve gauge up in the Santa Cruz Mountains 42.21.

Now through early November, before the first big storm. At Moffett Federal Airfield December, January and February are the wettest months of a normal year, and our schedule fills up once the forecast turns.

The U.S. Geological Survey counted over $150 million in landslide damage across the ten Bay Area counties, and San Mateo County had the most, about $55 million. Highway 84 was closed for four weeks after the February 2 storm, and on February 22 seven homes on Esplanade in Pacifica were evacuated as the cliff behind them retreated. Santa Clara County had about $7.6 million, including $500,000 of repairs on Montebello Road in the hills west of San Jose.

San Mateo County’s Department of Emergency Management says “Clear out rain gutters and downspouts,” Valley Water says “Keep rain gutters and downspouts free of debris,” and the Governor’s September 21, 2026 emergency release tells homeowners to clear drains and gutters and sign up for alerts. Your gutters are the first drain your roof water reaches, so cleaning them, flushing the downspouts and fixing leaks and sags before the wet months covers the part of that list that sits on your house.

Yes, if they are the right kind. BroGuard stainless micro-mesh keeps leaves and roof grit out while heavy rain passes straight through, so the gutter is open when a storm peaks. Foam inserts and plastic screens can clog or warp.