Hurricane Season and Climatology: When and Where Storms Happen

Hurricanes cluster in certain months and places for well-understood reasons. Here's when the Atlantic season runs and peaks, what an average year looks like, where the storms come from, and why some years are busier — plus why 'it only takes one.'

Hurricanes aren't random. They cluster in certain months and certain places, for reasons that are well understood — which is why “be ready before the season” is more than a slogan.

When the season runs

The Atlantic hurricane season runs June 1 to November 30. The eastern Pacific season starts two weeks earlier, on May 15, and the central Pacific (around Hawaii) runs June 1 to November 30 — all three end on November 30. Activity isn't spread evenly: the Atlantic builds through the summer and peaks around September 10 (the eastern Pacific peaks a little earlier, in late August), with most Atlantic major hurricanes from mid-August to mid-October, when the ocean is warmest and the atmosphere most favorable.

An average Atlantic season

Based on recent decades, a typical Atlantic season produces about 14 named storms, 7 hurricanes, and 3 major hurricanes (Category 3 or stronger). But averages hide huge year-to-year swings — and it only takes one landfall in your area to make a “quiet” season your worst.

Where they come from

Early and late in the season, storms often form close to home — in the Gulf of Mexico, the Caribbean, or just off the Southeast coast. At the peak, many of the strongest hurricanes begin as tropical waves coming off Africa and track across the deep Atlantic (the “Cape Verde” season), with time and warm water to grow. One reason this deep-Atlantic activity holds off until late summer is the Saharan Air Layer — a plume of dry, dusty African air that suppresses storms through the early season and fades after mid-August, helping activity ramp toward the September peak. Eastern Pacific storms, by contrast, spin up just off Mexico and Central America and usually track west or northwest over open water — so although it is a very active basin, it sends far fewer storms to the U.S. mainland than the Atlantic.

Why some years are busier

Large-scale climate patterns tip the odds. La Niña tends to reduce wind shear over the Atlantic and favor more storms; El Niño tends to increase shear and suppress them (in the eastern Pacific the effect flips — El Niño tends to boost activity there). Warmer-than-average ocean temperatures add fuel. Forecasters use these signals for the seasonal outlooks — but a seasonal total says nothing about where storms will actually hit.

Bottom line

The threat is real from June through November, sharpest around early September, and it only takes one. The time to prepare is before the season — a forecast of a “below-average” year is no reason to skip it.