The 2025 Atlantic Hurricane Season was a paradox in many ways. It was the first time in 10 years without a hurricane landfall in the United States and featured no hurricanes forming in or passing through the Gulf of Mexico [1, 2]. At the same time, 2025 saw 3 category 5 hurricanes form in the Atlantic, including Hurricane Melissa, which is tied for the third-most intense hurricane to ever form in the Atlantic. In addition, despite the impressive number of the most intense, category 5 storms, the overall number of storms that formed was near-average or even slightly below average compared with the last 30 years [2]. In this blog post, we will dive into these statistics and discuss what may have led to the 2025 season being so unusual.

Figure 1: Hurricane Erin churns off the U.S. East Coast. Due primarily to its large size, Erin churned up massive waves along many coastal areas of the eastern United States, despite never coming close to a landfall. Credit: https://satlib.cira.colostate.edu/event/hurricane-erin/

This year’s Atlantic hurricane season started off on a fairly normal note, with a series of weak, short-lived tropical storms followed by major Hurricane Erin in mid-August [1, 2]. Erin was the first category 5 of the season, a long-tracked, Cabo Verde hurricane that brought significant swells to large parts of the U.S. East Coast (see Figure 1) [2, 3]. After Erin dissipated, however, the season entered a prolonged period of inactivity, corresponding to the weeks when, historically, the Atlantic basin is the most active [1, 2]. This led to forecasters scratching their heads, with many wondering whether initial forecasts of above-average activity were inaccurate. Furthermore, this lull is similar to recent lulls we have witnessed in the 2022 and 2024 hurricane seasons, where much of the activity was backloaded towards the end of September and October, rather than around September 10 (which is the climatological peak season [4].

This inactivity quickly reversed around Sep 20, however, when Hurricane Gabrielle became the season’s second major hurricane, a category 4. From there, two more hurricanes ensued, category 5 Humberto and category 2 Imelda, which underwent a rare Fujiwhara-type interaction (see Figure 2) [5]. But the last storm to form and the one that truly made this hurricane season notorious was Hurricane Melissa, the strongest storm in recorded history to make landfall in Jamaica and the strongest to form in the world in 2025 (see Figure 3) [1, 2].

Figure 2: Hurricane Imelda (left) and Humberto (right) undergo a rare Fujiwhara interaction. Credit: https://satlib.cira.colostate.edu/event/hurricane-humberto/

Figure 3: The historic 24 hours before Hurricane Melissa made landfall in Jamaica with 185 mile per hour winds. Credit: https://satlib.cira.colostate.edu/event/hurricane-melissa/

Now that we have looked back on some of the highlights of the 2025 hurricane season, I want to talk about the factors that may have led to its unusual nature. Let’s first start with the formation of 3 category 5 hurricanes in a single season. The only other hurricane season to feature 3 or more category 5’s was 2005, the record-breaking year known for storms like Katrina, Rita, and Wilma [6]. Yet 2005 also broke records in terms of overall activity, with a record number of hurricanes and major hurricanes (tied with 2020), while 2025 did not have that same impressive feat. So what may be behind the fact that of the only 5 hurricanes that formed in the Atlantic in 2025, 3 were category 5 storms?

One factor is likely better observing systems. Even with plentiful satellite and recon missions in 2005, our observing systems have improved dramatically in the last 20 years, such that it is quite possible that storms that were classified as Category 5 in 2025 (such as Erin) may have been only classified as Category 4 in previous years [7]. In addition, the Atlantic Ocean in 2025, despite near-average overall activity, featured some of the warmest sea surface temperatures (SSTs) that we have seen in any hurricane season in the Atlantic, particularly in the Caribbean Sea and western Atlantic [1, 2, 8, 9]. For example, when Hurricane Melissa was passing through the central Caribbean in mid-to-late October, SSTs were as much as 1.4°C above normal; an analysis by Climate Central also found that these exceptionally warm SSTs were 500-800x more likely due to human-caused climate change [8, 9]. Their analysis also found that this would result in a wind speed increase, on average, of 9 miles per hour compared to if climate warming were removed [8, 9]. Indeed, multiple climate models show that in a warmer world, the number of extreme hurricanes (category 4/5) are likely to increase even if the overall number of hurricanes remains unchanged or even decreases (if you would like to read more about the impact of climate change on hurricanes, we have a blog series on that here) [10]. Therefore, while 2025 is just one year and it is impossible to draw definitive conclusions based on a single year, the oceanic conditions in the Atlantic Ocean in 2025 strongly favored more intense tropical cyclones, and it is no coincidence that these cyclones were at their peak while passing over some of the warmest SSTs compared to normal.

What about the fact that, despite the barrage of Category 5 events, no hurricanes made landfall on United States soil or even formed in or passed through the Gulf of Mexico? This can be explained by a combination of steering patterns and luck. A persistent trough of low pressure located over the eastern United States, coupled with a Bermuda High that was weaker and farther east than normal, led to many systems recurving to the east of the United States [1, 2]. The reason I say that this is partly due to luck is because it largely depends on the timing of when these systems form and the steering pattern at that moment. The steering pattern this year featured a trough on average over the eastern United States, but there were times when, if a system had formed and strengthened just a few days before or after, the steering may have been completely different. As such, this was a lucky year for the United States, thanks in part to upper atmospheric conditions that were largely unfavorable to U.S. landfalling storms.

2025 is also a reminder of the pace with which our world is changing. Paradigms that were used decades ago to explain the nature of hurricanes and climate may no longer apply today; and from here on out, Mother Nature is likely to continue to surprise us in more ways than one.

Questions about how to plan and protect yourself from the hazards imposed by tropical cyclones? Email us at sales@kinanco.com.

References

The 2025 Hurricane Atlantic Season in Review: A Year of Contrasts

Kinetic Analysis Corporation

The 2025 Hurricane Atlantic Season in Review: A Year of Contrasts

How Hurricane Melissa was Impacted by Climate Change: Part 2

Kinetic Analysis Corporation