A Strong El Niño Doesn't Guarantee a Wet Winter
First, a little context.
As of September 2026, NOAA's Climate Prediction Center expects El Niño to continue strengthening through the fall, with a very strong event likely to persist into winter 2026–27.
That sounds dramatic, but it doesn't mean every part of California will experience the same weather. A strong El Niño can influence weather patterns across the country, but it doesn't guarantee a specific amount of rain in Sacramento, Chico, Redding, Anderson, or elsewhere in Northern California.
That's an important distinction when we're talking about pests, too. El Niño itself isn't what changes pest activity around a home. It's the weather conditions that come with it that can make a difference.
So, if periods of heavier rain do develop in our area this winter, what should homeowners watch for?
Winter Rain Can Send Ants Looking for Higher, Drier Ground
Periods of heavy rain can have a noticeable effect on ant activity around Northern California homes.
Argentine ants and odorous house ants are two examples that Northern California homeowners may encounter. Many ants nest outdoors in soil, landscaping, and other areas around homes. When those areas become saturated or flooded, ants can relocate in search of more favorable conditions.
Sometimes that means moving closer to or inside a house.
Ants may enter buildings seeking refuge from flooded conditions and can suddenly appear indoors when weather conditions change. Odorous house ants are especially worth watching during wet weather because they are more likely to invade homes when rain disrupts their normal outdoor food supply.
That doesn't mean every rainy day will result in ants marching through the kitchen. But after periods of substantial rain, homeowners may notice ant activity in places where they weren't seeing it before.
If that happens, simply getting rid of the ants you can see doesn't necessarily address the colony responsible for the activity. Finding where the ants are coming from and identifying the species can help determine the appropriate treatment.
Rodents Are a Winter Concern With or Without El Niño
Mice and rats are a little different.
We wouldn't blame an El Niño winter for creating a rodent problem. Rodents live throughout Northern California regardless of whether a particular winter is unusually wet or dry.
Roof rats, Norway rats, and house mice remain active year-round in Northern California. As outdoor conditions change in fall and winter, homes can provide the food and protected shelter rodents are looking for.
Homes, garages, sheds, crawl spaces, and other structures can offer rodents access to shelter and potential food. House mice are particularly well adapted to living around people and can squeeze through openings as small as about 1/4 inch.
That makes fall a good time to check around your home for potential entry points rather than waiting until you hear scratching or find droppings.
The important takeaway is that rodent prevention matters during the cooler months, whether El Niño produces an especially wet winter or not.
What Should Northern California Homeowners Do Before Winter?
There's no reason to assume El Niño means your home is headed for a pest problem.
Instead, use the change of seasons as a reminder to look for conditions that could make it easier for ants or rodents to get inside.
Check around doors, windows, utility penetrations, vents, and the foundation for gaps. Keep food and garbage properly stored and address exterior areas that could provide rodents with shelter or easy access to the structure.
If heavy rain arrives, pay attention to new ant activity afterward. Ants suddenly appearing indoors can be responding to changing conditions outside rather than appearing out of nowhere.
Most importantly, don't wait for a weather forecast to decide whether your home needs protection. El Niño may influence this winter's weather, but the conditions around your property still play a major role in whether pests find their way inside.
Protect Your Home Through Winter With Big Time Pest Control
Whether this winter turns out wetter than usual or not, ongoing pest protection can help prevent ants, rodents, and other household pests from becoming a problem.
Big Time Pest Control is a locally owned and family-operated company that has served Northern California since 2001. With offices in Sacramento, Chico, Redding, and Anderson, our team understands the pest pressures homeowners face across the region.
Our residential pest control plans provide year-round protection with scheduled preventive services, exterior treatments, and interior service as needed. The Guardian Plan covers more than 30 common household pests, including ants, mice, and rats.
For homes with vulnerable entry points, Big Time also offers rodent exclusion. Our team identifies and seals the structural gaps mice and rats can use to get inside, helping prevent them from gaining access again.
If you're seeing ants, noticing signs of rodents, or want to protect your home before winter weather arrives, contact Big Time Pest Control to learn more about our residential pest control and rodent exclusion services.
