Something strange just popped up in the Gulf of Mexico: a hurricane. Well, not so much Hurricane Isaias, which storm-watchers expect to make landfall as a Category 2 somewhere between the coast of Mississippi and the Florida Panhandle late Friday, causing widespread destruction. It’s more the timing of it: This is the first Atlantic hurricane of the season, which began all the way back in June. That smashes the previous record in the satellite era for the latest first hurricane of a season, September 11.

“This is pretty astounding, really, to break a record by just about a month,” said Brian McNoldy, a senior research associate who studies hurricanes at the University of Miami.

So what’s with the extraordinary delay? El Niño, of all things.

Even though that band of warm water is on the other side of the Americas in the Pacific, it messes with two of the fundamental ingredients for making hurricanes in the Atlantic: wind and humidity. To spawn a tropical cyclone, you need warm water, which provides energy, as well as high humidity and winds moving in a consistent direction. (Hurricanes have been getting more intense lately because climate change is rapidly warming the oceans, creating high-octane fuel.) While the Atlantic and Gulf of Mexico have been plenty warm, providing huge pools of fuel, El Niño has been messing with weather patterns, creating dry, sinking air. It also provides wind shear — air moving at different directions and speeds as you gain altitude — which hurricanes really hate.

Hence the exceptionally quiet Atlantic hurricane season this year.

So why did Isaias finally break through in October? While it is indeed fighting wind shear in the Gulf, atmospheric conditions aren’t as bad for it as they are farther east. “It’s forming in one of the few places that a storm can occur in the Atlantic right now, because of the very strong El Niño that’s taking shape and imposing very strong vertical shear across the deep tropics,” McNoldy said. “The Gulf has a small window of opportunity for a storm to form, and it did.”

The Gulf is also running several degrees warmer than usual, at least at the surface, where Isaias is drawing its energy. Interestingly enough, though, the “ocean heat content,” a measurement of the thermal energy down through the depths, there is nearing a record low. “So that warmth is really only skin deep,” McNoldy said.

This sets up a weird dynamic for Isaias. Hurricanes are such violent storms that they churn up deeper waters: If that liquid is warm like the surface, that means more fuel. But if it’s cooler, that’s anathema to a hurricane. This effect is so pronounced that scientists can use satellites to trace the paths of hurricanes, just by detecting the trails of cold water they leave behind.

While the Atlantic hurricane season has been exceptionally quiet, in the eastern Pacific has been very busy as seven have formed, five of them being major. (It’s hosted 18 named storms so far, five more than usual.) Hawai’i has suffered particularly badly this summer, with hurricanes Lala and Nolo bringing torrential rain. Right now, Hurricane Rachel is taking aim at Baja Mexico and Southern California, where it could spawn dangerous surf and winds this weekend.

Meanwhile, the Gulf Coast is bracing for Isaias — a storm that may have arrived very late, but, with ferocious winds and a potential storm surge of up to 7 feet, is no less a threat for life and property.

This story was originally published by Grist with the headline Hurricane Isaias is a typical storm — but it’s also ‘astounding’ on Oct 8, 2026.

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