Hurricane Melissa (2025) and Climate Change
How oceans warmed by climate change are influencing this tropical cyclone
Climate change's effect on Hurricane Melissa (2025)
Hurricane Melissa reached Category 4 strength with peak winds of 140 mph by October 26 after undergoing extreme rapid intensification — an increase of about 70 mph in just 24 hours. According to the National Hurricane Center, the slow movement and rapid intensity of this system will create a "multi-day period of damaging winds and heavy rainfall, causing catastrophic and life-threatening flash flooding and numerous landslides. Extensive infrastructural damage, long-duration power and communication outages, and potentially prolonged isolation of communities is likely."
The storm is undergoing rapid strengthening as it sluggishly crawls over exceptionally warm ocean waters made 2.5°F (1.4°C) warmer, on average, and up to 700 times more likely due to human-caused climate change.
These unusually warm ocean temperatures, along with tropical climate warming, is forecast to strengthen Melissa’s top wind speed by about 9 mph, resulting in it becoming a Category 5 storm, and increasing its potential damages by up to 50%. If not for human-caused climate change, Melissa would have been a Category 4 storm at its peak.
Ocean influence along Melissa’s path
Melissa's status
Forecast information is provided by the National Hurricane Center. Not intended for public decision-making. Visit National Hurricane Center for official updates and more information.
Category 4
140 mph
How does climate change fuel more dangerous storms?
Human-caused carbon emissions trap heat in the atmosphere, and the oceans have absorbed about 93% of that excess heat since 1970. This is due to their vast depth and area, and seawater's higher capacity for retaining heat compared to air. Every tenth of a degree of ocean warming increases the risks of stronger storms and higher sea levels.
Warmer oceans provide more fuel for tropical cyclones, leading to stronger winds and greater potential damage. Potential wind-related damages increase roughly four times with each storm category jump (1 to 5), but even smaller increases in wind speed, without a category change, can dramatically raise the destructive power of a storm.
At the same time, rising sea levels caused by climate change can amplify the storm surge potential when storms occur, putting coastal residents at particular risk.
Finally, warmer air and oceans are leading to heavier tropical cyclone rainfall. These higher rainfall rates raise the risk of inland flooding, which has caused over half of hurricane-related deaths in the U.S.
Hurricane Melissa and rapid intensification
Hurricane Melissa experienced extreme rapid intensification over sea surfaces warmed by climate change.
Extreme rapid intensification refers to an increase in a tropical cyclone’s maximum sustained winds of at least 50 knots (about 58 mph) within 24 hours.
Melissa's maximum wind speed increased 70 mph in just 24 hours.
Learn more about the science
The Climate Shift Index: Tropical Cyclones (Tropical Cyclone CSI) builds on the foundation of our Climate Shift Index: Ocean (Ocean CSI).
Ocean CSI is a peer-reviewed system developed by Climate Central to measure the fingerprint of climate change on ocean temperatures. It indicates how human-caused climate change — driven by humans burning fossil fuels and emitting aerosols — has influenced the likelihood of daily sea surface temperatures at nearly any location around the world's oceans.
As ocean temperatures warm in response to climate change, they provide fuel for tropical cyclones (including hurricanes), increasing their wind speeds. Tropical Cyclone CSI, also developed from peer-reviewed research, quantifies this effect by calculating the increase (or decrease) in a tropical cyclone's wind speeds due to those warmed ocean waters and tropical climate warming.
Have questions about how we quantify climate change's impact on hurricane intensity, and how you can incorporate this data into your work? Explore our frequently asked questions here, or you can contact our team below.
Contact Climate Central's tropical cyclone attribution team
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