Climate Central Study: Autumns In U.S. Getting Warmer, Which Shouldn't Be A Surprise

A warm autumn day in my backyard. Photo was taken
on October 24, 2024. In past decades, the trees would
have been almost completely leafless by 
that time of year. 

Autumn is the new summer.  

That's an exaggeration, of course, but those brisk autumn breezes are fading under the weight of climate change. Summer weather is lingering longer across the United States. 

Climate Central has the receipts.

According to their latest report, autumn warmed in 98 percent of 245 major U.S cities analyzed, using data  from 1970 to 2025. The average increase in fall temperatures since 1970 is 2.9 degrees. 

The southwestern United States, northern Rockies an the Plains have warmed up the most. 

The fastest warming cities are Reno, Nevada (7.9 degree); El Paso, Texas (6.9 degrees)' Las Vegas (6.3 degrees); Tyler, Texas (6 degrees) and Tucson, (5.9 degrees)

Demonstrating the waning influence of natural variability, Climate Central found only three cities actually cooled a little bit in the autumn between 1970 and 2025.  But those cities barely got chillier, as they were only 0.2 degrees F cooler than they used to be.   

Besides climate change, a particular location's temperatures can be affected by El Nino and La Nina, an urban heat island effect, weather station relocations and other factors. 

For our Vermont readers, Burlington is in Climate Central's data set. The city warmed up by 5.2 degrees during the fall, nearly twice the national rate of warming. 

Climate Central's data looked at meteorological fall, which is the time period between September 1 and November 30. The figures come from open source data from NOAA. 

A warm fall up here in Vermont might seem nice. And it can be. Temperatures in the 70s in late October and early November are quite nice, especially since that time of year has a blustery reputation. But warm autumn weather can cause its share of problems.

Especially early in the season, lingering heat can be dangerous. For instance, in Kansas City this time of year, normal high temperatures are still summer like - in the low 80s. But each day during the first week of this month was in the 90s, with insufferable overnight lows in the 70s  

Lately, in recent years, horrible heat and humidity have lingered well into the autumn across large swaths of the nation. Including the north. 

Here in Vermont, it was 86 degrees in Burlington on October 5 last year. The year before that, temperatures were in the upper 70s to near 80 on Halloween. In the past, it's been known to snow here when trick or treaters roam the streets of the Green Mountain State. Not any more, apparently. 

Climate Central lists other effects of hot autumn. Among them: 

Kids go back to school in the fall. Many schools, especially in the northern half of the U.S.,  have no or inadequate air conditioning, making it a challenge for both learning and student health. And the teachers are suffering, too. 

Hot, dry autumns extend the wildfire season, especially in the western United States. The worst case scenario was probably the Paradise, California fire on November 8, 2018. The fire killed 85 people, making it the deadliest wildfire that nation has seen in the past 100 years. The wildfire destroyed 18,000 structures, including 9,000 homes.  

By early November, the first early rains should have hit that part of California. But it was late, setting the stage for the calamity. 

Back here in Vermont, fall foliage season is coming very soon.  Eventually, climate change could ruin the magic, and the tourism dollars that come with it. So far, I see no evidence the brilliance of the season is waning, but it has been generally getting later. In the warmer Champlain Valley, you now have to wait until the second half of October to see peak foliage. 

The growing season is lasting longer, which is great for farmers and gardeners. But people with allergies suffer as ragweed and other such plants don't die so early. Also, ticks, mosquitoes, and other bugs last longer into the fall.  

Despite Current Endless Winter in Vermont, Winters Are Getting Shorter Nationwide

A graphic from Climate Central shows how winters in
Burlington, Vermont have gotten shorter in recent
decades. This winter is an exception to the trend.

Here in Vermont, and the rest of New England, this winter has seemed endless. It feels like it's been going on forever, and it seems like we'll never be finished with it. 

But this long winter is an exception. Winters overall have been getting shorter, thanks to climate change. 

Climate Central waded through data from 245 American cities and found that in 195 of those cities, the coldest part of winter is on average nine days shorter than winters were between the years 1970 and 1997.

Here's how the study worked, according to Climate Central:

"This analysis defined winter as the coldest 90 consecutive days of the year during the past (1970-1997) and then compared the frequency of those winter-like temperatures during the most recent 28-year period (1998-2025)."

Juneau and Anchorage, Alaska have seen winters shrink the most, by 62 and 49 days respectively. That makes sense, since warming is much faster in northern latitudes and the Arctic. I would note that like here in Vermont, Juneau and Anchorage are bucking the trend this winter as it's been unusually cold and snowy this winter in Alaska. At least compared to recent winters. 

Climate Central's analysis included Burlington, Vermont, where winters are 17 days shorter than they once were.

In 1970-1997, the coldest 90 days pf winter on average started on December 9 and ended March 8.  Now, the period with those coldest temperatures only goes from December 20 to March 2. 

Not everyone is experiencing shorter winters. 

Reflecting the fact that in some cases, regular variability and other factors besides climate change can keep winters relatively long. A few cities in the Ohio Valley have winters as long now as the once were. So, too in parts of California, though the ocean's influence there limits large seasonal temperature swings.  

Even if you like these shorter winters, there are downsides to these milder seasons. 

As Climate Central notes, warmer, shorter winters can reduce mountain snowpacks, especially in the western U.S. That can lead to summer water shortages and an increased risk of wildfires. 

Sometimes, a lack of winter chill prevents fruit and nut trees and plants from getting enough of a cold cycle to adequately produce crops int the following growing season.  Warm winters can also prevent pests like ticks from dying off. A shorter winter could also mean the spring allergy season might last longer. 

Here in Vermont, as noted, we have had a long, cold winter, bucking the trend Climate Central has outlined. But the trend toward shorter, warmer winters will continue. A season like the winter of 2025-26 will keep getting increasingly rare.  

Climate Central Takes Over Billion Dollar Disaster Database That Trump Administration Abandoned.

Climate Central has taken over a data base of
billion dollar disasters in the United States.
The federal government had maintained the
data, but the Trump administration ended
it because they don't want to 
acknowledge climate change. 

Weather and climate science runs on data.

The more data you have, the better information you have, the better judgement you'll have, the better prepared you'll be.  

As I've noted numerous times, the Trump administration has been cutting back on the tools scientists need to keep track of the weather and climate.

One of the things gone is a data base of disasters that cost a billion dollars or more. 

The Trumpsters hate anything that shows climate change is causing trouble, since they insist climate change doesn't exist.

So they decided if climate driven disasters aren't reported, they don't exist. 

Or something like that. 

AsABC News Explains: 

"But in May, the Trump administration announced it was shutting down the website that hosted the dataset. That made it difficult for the public and experts to track the impact of major disasters, as the program used a combination of private and public data, some of which was not available to organizations outside the government."

Obviously, anyone who cares was bummed about the loss of that information. 

However, the data is coming back. Climate Central, a non-profit organization that communicates climate change science, affects and solutions to the public and policy makers. 

A guy named Adam Smith is running and managing the billion dollar disaster data set. He managed the billion dollar list at NOAA, but he was let go by the Trump cutbacks. He is now Climate Central's Senior Climate Impact Scientist. 

ABC continues:

"'The billion dollar disaster analysis is vital in demonstrating the economic impact of extreme weather and climate events, which helps communities understand the real-world consequences of climate change and the increasing impact of these different events," said Smith. 

'I would also say this dataset was simply too important to stop being updated,' Smith added. 'We've seen a widespread demand for its revival from many aspects of society and industry, including the private sector, academia, local community decision makers, even Congress,'"

Climate Central replicated all the data sources for the disaster report, so the information going into it is equivalent to what we used to see on the federal NOAA website.  They'll also use the same peer reviewed methods as the NOAA version did. 

The billion dollar data base isn't the only set of information being rescued from the follies of the Trump administration. 

The Trump administration pretty much got rid of the web site climate.gov, which was the go to place for comprehensive, accurate climate information. The site now directs you to noaa.gov, which has some climate information, but nothing nearly as comprehensive as what was once on the site. 

A non-profit developed an alternative site called climate.us that has much of the information that was removed from climate.gov. 

THIS YEAR'S DISASTERS, COMPARED

According to the revived data compiled by Climate Central, so far this year, the United States has had 14 disasters costing $1 billion or more. (This is all inflation-adjusted).

Mostly because of the incredible wildfires around Los Angeles in January, the cost of this year's disasters are so far is running well above average. The fires alone cost more than $60 billion in damage.

Through June big U.S. disasters have cost $101.4 billion. Most of them involved, tornadoes, severe thunderstorms and flooding. 

This means even if no other big disasters hit this year, 2025 will end well above the average of $67.3 billion. 

However, 2025 won't necessarily be the most costly year on record, despite the strong start. Years with large hurricanes in the U.S. tend to be the most expensive, The year 2017 was the most costly, in large part because of Hurricanes Harvey and Irma, with $405.2 in damage.

 Next was 2005, which included hurricanes Katrina and Rita, with $275.5 billion in overall damage. 

It looks like no big hurricanes will hit the U.S. this year. (Forecasters worry Tropical Storm Melissa will turn into a giant hurricane, but most predictions expect that storm to have relatively little effect on the U.S. 

If no other billion dollar disasters happen this year, it looks like 2025 would be the eighth most expensive since 1980, which is the beginning of the data base record.

The disaster total will probably go up for this year. Four other disasters are still being assessed to determine whether they cost at least $1 billion. These include the horrible, deadly July 4 weekend floods in Texas, and three severe weather outbreaks between May and August.  

And gawd knows what the final two months or so of 2025 might bring. 

 

Spring Showing Warming Trend Over The Years In Most Of U.S.

As this map from Climate Central shows, spring has warmed
across all of the continental U.S. except the northern
Plains since 1970,

I don't know how this spring will turn out, but like everything else associated with climate change, spring in the United States is different than it used to be. 

 Climatecentral.org tells us that on average spring is now 2 degrees warmer in the U.S. than it was in 1970.

The Southwest has warmed the most, with places in Nevada, Texas and Arizona having a warming of at least 6 degrees since 1970.

.Climate Central looked at 238 weather stations in the United States during meteorological spring, which is defined as the period between March 1 and May 31. 

All but six of those locations are warmer now during spring than they were in 1970, according to the data. 

An earlier and warmer spring has pluses and minuses. Since the last spring frost on average is coming earlier, growing seasons are being extended some.  Even that's a double-edged sword. Weather and climate have become much more variable than they once were - with extended warm periods punctuated with brief cold snaps that can damage crops that are blooming too early. 

We might see that this year. The Southeast and parts of the Mid-Atlantic States have been experiencing record early spring blooms in February and so far this March.

Since everything from blueberries to peach blossoms and cherry blossoms are sprouting much earlier than normal. All it takes is one nasty frost to wipe all that out. I notice that below normal temperatures are in the forecast for the Southeast and Mid-Atlantic coming up in next week or two could endanger crops. 

Warmer and more abrupt springs are also causing early and more intense pollen attacks, a situation I'm sure people with allergies must absolutely adore. 

In the West, drought conditions have been exacerbated by earlier spring snow melt in the mountains. Water from the melting snow rushes off the mountains prematurely, leading to much less needed water from mountain streams and rivers later in the summer. 

Given the huge amounts of mountain snows in many Western mountain areas now, this year could be an exception.  There might be so much snow up there that melting would continue into the summer. 

Or, who knows? It could really turn hot in April, melting the snow in a flash - and resulting flash flooding - before returning the region to drought. 

For some reason, North Dakota and parts of South Dakota have actually cooled in the spring a bit since 1970.  I'm not sure why. It might have to do with increased snow cover early in the spring. Snow reflects sunlight, which makes things cooler than they otherwise would be.

A trend toward no-till farming might be having a cooling effect in late spring in summer across the Plains. The cover crops increasingly in place add humidity to the air, which can cool temperatures somewhat. 

Judging from Climate Central's map, Vermont's spring is warming slightly more slowly than the national average, having risen by between 1 and 2 degrees since 1970.  Winter is Vermont's fastest warming season. 

For much of the nation, spring is getting off to a rare chilly start this year. Temperatures through about the third week of the month are expected to be below normal for a majority of the Lower 48.  Of course, that doesn't mean the whole spring will be chilly. I expect true to form, we'll have some very odd hot spells somewhere in the nation between now and Memorial Day.