We are heading into August, which typically marks the transition from hurricane season's slower opening months to its main event that continues through September and into October, when the majority of tropical storms and hurricanes develop.

Heart Of The Hurricane Season

Visualizing The Peak: In the graph below, you can see the historical frequency of tropical storms and hurricanes ramps up sharply by mid-August, peaking in September. It's not until after the midpoint of October that activity significantly trends downward into the hurricane season's final month of November.
How Many Storms? Based on the 1991-2020 average, August through October has produced an average of 11 to 12 named storms. That's a huge chunk of the entire six-month-long season average of 14 named storms from June through November. Put another way, about 92% of a hurricane season's activity — using a metric called the ACE index — happens from August through the end of the season.
Peak Of US Hurricane Landfalls, Too: 93% of hurricane landfalls along the U.S. Gulf or East coasts have occurred from August through October, according to NOAA. That said, you should still have your hurricane season plan in place before the June 1 start of the season since tropical storms and occasional hurricanes can still bring serious impacts before the peak season arrives, as we saw with Beryl last year.

Why The Peak

When compared to early in the season, a much larger expanse of the Atlantic is primed for the development of tropical storms and hurricanes in August and September, as shown in the maps below. That's because of several factors in the atmosphere and ocean that become more favorable, including:

Tropical Waves Are More Defined: These atmospheric disturbances often act as a seed for tropical storms and hurricanes to form. About 60 of them emerge from Africa and track westward through the tropical Atlantic during the season, but it's not until the peak months that they have the greatest chance to help spawn a named storm.
Dry, Dusty Air Diminishes: Surges of Saharan Desert air from Africa into the central and eastern Atlantic Basin that normally squelch tropical development in those areas tend to give way by August as the parade of tropical waves mentioned above gradually adds moisture. This opens up more favorable real estate for tropical storm development.
Wind Shear Decreases: This change in wind speed and/or direction with height, which can rip apart a tropical storm wannabe, tends to be lower in the peak months.
Sea-Surface Temperatures Are Warmest: The ocean waters are still warming early in the season and don't rise toward a peak until late summer and early fall, providing more potential energy for a tropical storm to form.
Instability Increases: This refers to the atmosphere's ability to generate convection (thunderstorms). More unstable air this time of year helps thunderstorm activity to persist long enough in order to help spin up a budding tropical storm.

More To Know

It's A Destructive Time: We don't need to go back far to see how the peak months often generate hurricanes that pack a major punch. Many of these hurricane names should sound familiar from the past five years:

2024: Helene (Florida, Southeast); Milton (Florida)
2023: Idalia (Florida's Big Bend)
2022: Fiona (Puerto Rico, then Atlantic Canada); Ian (Florida)
2021: Ida (Louisiana, then deadly flooding in the New York City area); Nicholas (Texas)
2020: Isaias (North Carolina, East Coast); Laura (Louisiana); Sally (Florida/Alabama border); Delta (Louisiana)

Sometimes A Hyperactive Switch Is Flipped: Two of the most active hurricane seasons started very quietly. 2004 was infamous for Florida's big four hurricanes — Charley, Frances, Ivan and Jeanne. But all that season's activity waited until Alex became a tropical storm on Aug. 1. In 1969, only Tropical Storm Anna formed before August. But that was followed by an onslaught of 17 storms, 12 of which became hurricanes from August onward.

Historical trends like the ones mentioned in this article are no guarantee of how the peak of the 2025 hurricane season will turn out. But, you should make sure you have your hurricane plan ready to go and pay attention to the forecast every day through the rest of the season.

Chris Dolce has been a senior digital meteorologist with weather.com for 15 years after beginning his career with The Weather Channel in the early 2000s.