Two months into the Atlantic hurricane season, the United States has largely been spared, with only two storms, Arthur and Bertha, having grown strong enough to merit official names. That’s about what meteorologists expected when they said this year’s hurricane season would probably see fewer storms than most other seasons.

Off the West Coast of North America, however, things look a little different: There have been seven named storms since the season began. The most recent, Genevieve, became a Category 5 hurricane in late July, the strongest storm in the region in nearly two years.

On Wednesday, experts with the National Hurricane Center were monitoring a few clusters of thunderstorms roughly halfway between Mexico and Hawaii, each of which had some chance of becoming a named storm in the next week.

Storms that form in the Pacific generally move west, away from mainland North America. So although Genevieve was especially intense, it was also mostly harmless as it moved through open waters.

But thanks to El Niño, the Pacific Ocean faces a higher than normal risk of hurricanes this year — increasing the likelihood that a major storm will break from this predictable path and strike California, Mexico or Hawaii, federal meteorologists have warned.

“The ones that turn are a challenge, for a number of reasons,” said Jamie Rhome, the deputy director of the National Hurricane Center.

The last El Niño season, in 2023, produced several extreme storms that did just that: Hurricanes Otis, Hilary and Norma, each of which created what Mr. Rhome called a “messaging conundrum” for the Hurricane Center, which is tasked with explaining complex threats to a population that is largely unfamiliar with hurricanes.

The 2026 Forecast

Two regions can potentially affect these areas: the Eastern Pacific and the Central Pacific. In their predictions this spring, forecasters at the National Oceanic and Atmospheric Administration said both were likely to experience above-average seasons. The Eastern Pacific, which is closest to California and Mexico and traditionally experiences 15 named storms, could expect between 15 and 22 this season; the Central Pacific, surrounding Hawaii, could look forward to between five and 13 named storms or depressions, compared with its typical four or five.

The California Risk

While tropical systems are exceedingly rare in California, El Niño seasons do occasionally steer them north toward the state. In 2023, Hurricane Hilary prompted its first-ever tropical storm watch, sparing the immediate coast but unleashing historic flooding that filled Death Valley for months with a lake.

Only two known tropical systems have made direct landfall in the state. An El Niño-fueled tropical storm hit Long Beach in 1939, killing nearly 100 people and destroying coastal property, according to the New York Times archives. Before that, a hurricane struck San Diego in 1858 during a period of unusually warm coastal waters. (Hilary in 2023 actually made landfall in Mexico, but still brought tropical storm conditions to Southern California and enough flooding in Death Valley to close the park for the longest duration in its existence.)

Hurricanes require sea-surface temperatures of at least 26 degrees Celsius (79 degrees Fahrenheit) to maintain their intensity. California is typically shielded by a band of cold coastal water that saps a storm’s energy.

Jonathan Suk, the meteorologist-in-charge at the National Weather Service in San Diego, said earlier in June that coastal temperatures remained well below that critical threshold, but that the staff would be monitoring them closely. Sea temperatures in Southern California have warmed since that time, with a marine heat wave off the coast that is predicted to last through the end of the year. Yet as of this week, surface temperatures in the area stood slightly below the most intense records and the level needed to support a hurricane.

The Hawaii Risk

An outlook of five to 13 Central Pacific systems is “a significant forecast,” said Derek Wroe, a meteorologist with the Weather Service in Honolulu. The heightened risk arrives as the islands recover from record-setting spring rains. The active forecast hinges on how powerful El Niño becomes ahead of the region’s peak hurricane months, which opened in July and last through September.

Even distant storms can be dangerous. In 2023, the winds from Hurricane Dora, which passed far south of the islands, helped fuel the catastrophic Lahaina wildfires on Maui. In 2024, Hurricane Hone passed within 60 miles of the Big Island, cutting power to thousands and snapping native trees.

Yet landfalls remain exceptionally rare. Since 1950, 19 hurricanes have passed within 100 miles of Hawaii, but only two hit directly: Hurricane Dot in 1959 and Hurricane Iniki in 1992. Both struck during neutral weather patterns and not El Niño seasons. Even during a particularly strong El Niño in 2015, when 14 storms entered the basin, Hawaii never had to issue a hurricane warning.

The Risk to Mexico

Mexico faces the highest risk because it borders the basin’s warmest waters. While most Eastern Pacific storms move west into open water, some curve back toward Mexico’s extensive coastline.

The primary anxiety for forecasters is rapid intensification. During the 2023 El Niño season, Hurricane Otis exploded into a Category 5 storm overnight before devastating Acapulco.

“Otis is the classic signature storm that keeps you up at night,” Mr. Rhome said. “A rapid development right at the coastline and overnight.”

‘Every Storm Is Different’

Forecasters worry recent near-misses that didn’t produce much lasting damage — like Hilary in California or Hone in Hawaii — will breed complacency.

“People often use the last storm they experienced to dictate how they behave,” Mr. Rhome said. “Every storm is different.”

A lower-than-normal forecast for the Atlantic could also lull residents into a false sense of security, even though the projected storm counts there equal those of the active Pacific. Mr. Rhome, who lives in Florida, isn’t taking chances. He is already checking his emergency supplies and testing his generators.

In California, Mr. Suk explains that the state’s residents and weather experts have a very distinct, multipronged preparedness culture.

Unlike their East Coast counterparts, who primarily focus on hurricanes, California meteorologists and emergency officials have to balance tropical threats against a constant backdrop of other extreme hazards, including earthquakes and wildfires.

“Hilary was definitely something that surprised a lot of folks,” Mr. Suk said. “Here in the National Weather Service and those that work in emergency management, we always knew that there’s a chance that happens, and it’s one of the things that we do train and we do prepare for.”