Hurricane Milton made more intense by climate change, study finds

Jeff Berardelli is WFLA’s Chief Meteorologist and a climate specialist.

When Hurricane Milton was over the record hot Gulf waters, it was one of the strongest hurricanes ever recorded in the Atlantic Basin, with winds topping out at 180 mph.

It rapidly intensified 120 mph in 36 hours tying a record for the Atlantic. And as it moved across Tampa Bay it dropped a wide swath of torrential rain, flooding out whole neighborhoods — some still under water.

Strong winds and heavy rain are nothing new to hurricanes, but in recent decades, hurricanes have been made worse by our warmer climate. Now, a rapid attribution study from World Weather Attribution finds that Milton was made significantly more intense — both the rain and the wind — by climate change.

When Milton moved across the Gulf of Mexico a week ago, water temperatures were the hottest ever recorded . This is not an isolated incident. The Gulf and the Atlantic Basin as a whole have been warming steadily for decades. Last year was the hottest ever record until this season when much of the basin tied or surpassed last season’s record-shattering heat.

Heat has been building up in the Earth system for the past century due to human-caused climate change, fueled by the release of heat-trapping greenhouse gases from the burning of fossil fuels. About 90% of the excess heat, which builds up in the climate system, is retained by the oceans.

This excess ocean heat provides more energy to developing tropical systems, which can make them intensify more rapidly, become stronger, and especially dump heavier rainfall. And that is exactly what this new study has found.

World Weather Attribution is an organization made up of dozens of the World’s top climate scientists. They examine the most extreme weather events in the world to see to what degree climate change may have impacted them.

For Milton, they found the storm was made about 10% more intense. In other words, Milton was likely up to a category stronger than it otherwise would have been without climate change. So winds of 165 mph today would have likely been closer to 150 mph a century ago.

The team also found that a storm of Milton’s intensity is 40% more likely today than it would have been in the early 1900s. While it may seem that these changes in intensity are modest, the reason this matters is that just slight increases in a hurricane’s intensity equates to exponentially more damage .

An even more direct link between a warmer climate and extreme weather is heavy rainfall. There is a straightforward relationship between warmer air, warmer water, and heavier rain. Indeed, the study found that Milton’s rain — which is still flooding homes in the Bay Area — was enhanced significantly by climate change.

The Tampa Bay area piled up a swath of 10-18″ of rain mainly from the bay northward — a feat that should occur less than once per century. St Petersburg broke an hourly record with over 5 inches in one hour. The team found Milton likely had 20-30% more rainfall than it otherwise would have in a cooler climate.

Finding a link between hurricane rainfall and climate change is very common. Just two weeks ago, a study found that Hurricane Helene’s rainfall — which caused catastrophic flooding — was likely boosted by up to 50% in parts of the Southeast U.S.

These findings of stronger, wetter hurricanes are consistent with what WFLA found in its summer hurricane study. We examined how hurricane landfalls would change in the 2nd half of this century by localizing a 2023 Department of Energy study. The findings were astonishing but not that surprising given the level to which climate change is already impacting hurricanes.

In the Tampa Bay area, we found that major hurricanes will occur three times more often than they have historically, storms will produce up to 50% higher rainfall rates, and 15-20% higher wind speeds. This is assuming we continue to warm the Earth at the same pace we are now.

Those changes are generally true for all of Florida, not just Tampa.

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