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.  

A Surprisingly Wet Morning North, But Vermont Weather Should Improve This Afternoon

Weather radar showed a solid band of rain across 
northern Vermont as of 8 a.m. this morning. A weak 
cold front was creating a little more rain than
expected, but some sunshine should break out later today

We knew a weak cold front would drift into northern Vermont this morning, with clouds and maybe a few sprinkles.  

However, the rain in the north was more widespread this morning than we thought. Which is a good thing. We needed the rain. 

At 8 a.m., weather radar showed widespread, mostly light rain covered Vermont north of Route 2. There were some moderately heavy spots of rain in this mass of sprinkles, drizzles and small raindrops.  

Despite continued forecasts for only a couple hundredths of an inch of rain, it looks a few lucky devils will get between a tenth and a quarter inch of rain.  Not huge, but we'll take it. Especially where some decent wetting hit the drought area in the Northeast Kingdom. 

The cold front, and the rain was slipping southward as of 8 a.m., so the rain will move south as well. It'll start to break up as it heads south, as the cold front itself is falling apart, too.  The showers in northern Vermont will gradually become more and more scattered and fade. The sun should come out, too, mixed with lingering clouds. 

Southern Vermont won't get any rain at all out of this.  They will have just a partly sunny day. Maybe an isolated shower in the mountains. Region-wide, highs will reach the 70s. 

We do have some more rain coming this week, too.

WEDNESDAY

The next, somewhat more powerful weather system will start to affect us.  We'll see increasing clouds, increasing south winds, increasing humidity, and eventually, increasing chances of showers. Especially north. 

Highs should reach the 70s again. 

WEDNESDAY NIGHT

I'm hoping we don't have another rainy forecast bust, like last week. On September 2, we expected a statewide, soaking nighttime rain. Instead, the only substantial rain hit the far north. This time, meteorologists expect the rain to concentrate itself in the north again, but a little rain should hit the far south, too. We hope. 

In any event, current forecasts call for a decent half inch to an inch of rain in the northern half of Vermont, a quarter to half inch in central Vermont, and less than a tenth of an inch in the far southeast. 

It'll be a muggy night, too as a squirt of humid air will try to sneak in. Very briefly. This weather system is blowing through quickly, so the hint of summer won't last all that long.

THURSDAY

Lingering morning showers will taper off, revealing a partly sunny, breezy, warm day. The morning humidity will fade, leading to fresher, afternoon air.  Highs should hit 80 degrees or so, probably one of the last such days of the year.  At most, we'll only have a handful of days that hit 80 before autumn really takes hold.

FRIDAY/SATURDAY

Delightful weather, the kind Vermont in September is famous for.  Daytimes will feature sunshine and highs in the 70s, with Saturday being the slightly warmer of the two days. 

Overnights will be cool, with lows in the 40s for most of us. As usual for this time of year, patchy dense fog will envelope river valleys early in the mornings. 

SUNDAY AND BEYOND

We might eke out another nice day Sunday, and then the next system will return a chance of showers early next week.  

Hurricanes Harassing Hawaii, California, East Coast Remarkably Storm-Free

Hurricane Lowell in the Pacific Ocean on Monday. Hawaii
is hidden beneath the clouds. 

For the second time within a month, a hurricane is threatening Hawaii. 

Hurricane Lowell has taken its northward turn, but it has been heading a little east of north. That means the Hawaiian Island will have more trouble than originally thought.  

The hurricanes expected path has shifted about 75 miles east since Sunday morning. Hurricane Lowell is expected to pass within 75 miles of Kauai as a category 2 storm tonight and tomorrow. 

It still looks like most of the Hawaiian Islands will be spared hurricane force winds, though a hurricane warning is in effect for the islands of Kauai and Nihau. Winds could gust to 85 mph later today and tonight, and 10 to 15 inches should drown the western islands. 

But torrential rains and tropical storm force winds could hit the entire island chain while the storm passes by. 

A tropical storm warning is in effect for Oahu, which includes the city of Honolulu. Kauai and Niihau could receive six to 10 inches of rain with local amounts of 14 inches. Normal September precipitation the islands is between two to four inches. So flooding is inevitable.   

The rest of the island chain can expect four to eight inches of rain. Which is more than enough to cause flooding and landslides. Especially after other recent storms on the island. 

The islands are also going to be battered by huge waves and storm surges.

Hawaii Gov. Josh Green declared a state of emergency for the entire state. The Hawaii National Guard  has been activated. 

All this comes less than a month after Hurricane Lala sideswept Hawaii, causing enormous flood and mudslides especially on the Big Island. One spot on the Big Island had 43.54 inches of rain as the hurricane passed by just to south of Hawaii.

HURRICANE MARIE

Meanwhile, Hurricane Marie moved north to northwest out in the Pacific Ocean, far to the southwest of California. By today, it was over cooler water, and it had weakened to a tropical storm. 

Still, it was able to last longer than most hurricanes that get that far north, due to oddly warm water. The storm is throwing immense waves at southern California, 

Some waves on south facing California beaches reached ten feet high. Video showed waves smashing into seaside homes and condos, flooding garages and some lower floors. Parking lots were inundated. 

The National Hurricane Center said that dangerous surf conditions would continue today and tomorrow..

Moisture streaming off of Marie caused some unseasonable showers in southern California. It's also unusually humid in southern California because of the moisture from Marie, and because offshore waters are unusually warm. Heat advisories are in effect through Thursday as a result.

The humid air might also prompt tropical-like thunderstorms, which are exceptionally rare for southern California. 

 Meanwhile, in the Atlantic Ocean, which should be busy with tropical storms and/or hurricanes now, is still strangely quiet at the peak of the normal season. The National Hurricane Center says no tropical storms are expected over the next seven days.  

Another Sign Of Autumn This Morning, Then Quick Blip Of Humidity, Rain

Henry the Weather Dog at the dog park in
St. Albans, Yesterday. The sun was out at
the moment this photo was taken, but
under clouds and with gusty north winds
it actually felt chilly at times. Autumn
is definitely showing itself. 

For the first time since maybe early June, I felt chilly for awhile Sunday afternoon.   

The highlight of the day for Henry the Weather Dog is a trip to the dog park here in St. Albans. I brought him there in my usual summer uniform: Shorts, a t-shirt, sneakers. 

It was 70 degrees out at best. Warm enough for that outfit. But the sun occasionally disappeared behind large, poofy clouds, so that cooled the air occasionally.  The wind also blows hard at the dog park, as it's funneled between Hard'ack Hill to the west and French Hill to the east. 

The result: I felt chilly. 

I'm not whining. It's not as if I was dying of hypothermia. Still, I took my goosebumps as a sign we are sinking deeper into autumn. 

And it was cool this morning too. It was 50 degrees in Banana-Belt Burlington this morning. It got down to 41 in Bennington and 42 in Morrisville and Lyndonville. 

The arrival of autumn comes in waves, the cool air interspersed with periods of warmer, even summery weather. So the vaguely nippy air we just had will relax into warmth. Let's get into the details.

TODAY

Temperatures have started rocketing upward and will peak well into the 70s this afternoon.  Maybe close to 80 in the warmest valleys. Henry's trip to the dog park today will not result in any shivers today. Sunshine will reign supreme. Get outside and enjoy!

TUESDAY

An extremely weak cold front should drift down from Quebec early in the morning. It'll probably bring a band of clouds. Maybe even a widely scattered light shower or sprinkle in the north. But the sun should partially make an appearance in the afternoon. It'll be a couple degrees cooler than today, but still in the 70s

WEDNESDAY

The next weather system will start to come at us from the west. South winds will pick up, and those south winds will pick up some humidity from the Gulf of Mexico and throw it at us. It'll start to feel sticky, and we'll have a rising chance of showers in the afternoon. 

A brief spell of very humid air will help blossom a period of rain, maybe briefly heavy overnight Wednesday/Thursday. There could even be a downpour or two. But the rain will rocket through here so fast Wednesday night it won't have a chance to give us all that much. 

We might see over a half inch of rain in northern Vermont, maybe a quarter to a half in central Vermont and the Champlain Valley, and less than a quarter inch far southeast. Of course, there might be adjustments to the forecast.

THURSDAY-SUNDAY

September in Vermont is famous for its spells of delightful weather. Sunshine, low humidity. With few springtime gnats or mosquitoes buzzing around and no mud underfoot. 

We might have a couple lingering showers Thursday, especially in the morning. Humidity will probably linger in the morning, too, but the air should start to feel more fresh in the afternoon. It'll be warm, as it could get up to 80 degrees or so. Not near any records by any stretch of the imagination, but a little warm for September. 

As it looks now, Friday and Saturday look delightful. Sunshine, maybe a few puffy afternoon clouds, with afternoon highs in the 70s. Both mornings will feature dense fog in the river valleys. That's also classic September weather. 

It's possible some light showers come back into the picture later on Sunday, but we might well squeak out another nice day.  

The United Nations Has Finally Given Up On Its Tenuous Hold On Climate Optimism

The United Nations has finally admitted that the goal of
keeping the world from becoming 1.5 degrees warmer
than the 18 century average. 

The famous 1.5 degree Celsius climate change goal is officially kaput. 

That figure was the goal set during the international 2015 Paris climate accord. 

According to that decade old plan, the world wasn't supposed to get more than 1.5 degree Celsius or 2.7 degrees Fahrenheit above the mid 19th century average.   

The UN is throwing in the towel with that one. Many other climate experts have been saying for months or even years that the world would not achieve the goal.  

The 1.5 degree target is still nominally the UN's goal, but they've finally admitted it's completely unrealistic. So, it's now all about trying to deal with the hotter world. 

As CBC reported:

"In a strategic retreat in the fight against climate change, the United Nations has acknowledged that Earth has lost its chance to prevent some of the worst of global warming's harms. Officials say the world must now figure out how to get temperatures below the danger zone and back to safety."

The trick now is to figure out over the next several decades how to get the world's temperature back under 1.5 degree C above the 19th centurial average. 

As the Associated Press reports: 

"Instead of giving up, scientists and the U.N. officials recommend trying to limit excessive warming and then bring the temperature back down to the agreed-upon threshold. But it will still mean decades of increased weather-related disasters rising seas, extinctions and melting ice and glaciers."

The 1.5 degree Celsius threshold is rather arbitrary. It's not like things will be OK until we reach 1.5 degrees, then all hell breaks loose. 

As the world has warmed, we've seen a gradual increase in record heat waves, destructive, wild storms and deepening droughts. 

Things will  just get worse and worse the higher the temperatures get. But you need to have goals, and that 1.5 degrees was the global goal, set by the U.N. 

The time for that goal has passed. The world is now 1.4 degrees hotter than it was in the 19th century. This is based on a 20 year average. The next couple of years will boost the average further, considering a strong El Nino will warm the world further. 

The U.N's latest most optimistic scenario now has the world's warming peaking at 1.8 degrees Celsius, or 3.2 degrees Fahrenheit about levels that we saw nearly two centuries.  Then, the hope is, the world would eventually start to cool back down a little. 

This is if countries around the world pursue ambitious climate goals starting now. Good luck with that. I'm looking at you, United States. 

To do this, the world would have to cut planet warming pollution 55 percent by 2035, then getting rid of virtually all fossil fuel emissions by 2050 or so. I do not see the political will do this. Correct me if I'm wrong. 

Washington Post explains the consequences: 

"The dangers at the scale of warming will still be significant. Rising sea levels will engulf small island nations and submerge many coastal communities. Heat waves, hurricanes, wildfires and floods, which already cause hundreds of thousands of deaths each year, will come many times more extreme. Without aggressive adaption measures, global food production could decline by 14 percent."

Also, even if we get above that 1.5 degree threshold for several decades, then manage to go below it again, it won't solve all the problems the world's warming has caused. Perhaps a quarter of the world's glaciers will have permanently melted away. Species will go extinct. Some ecosystems will never recover. 

If nothing changes in terms of policies, global temperatures will rise to 2.6 Celsius (4.7 degrees F)  over mid-19th century levels.  Per the AP:

"The UN's report says every five years of delay in reducing emissions adds at least a tenth of a degree to peak warming, said report co-author Joeri Rogelj, a climate scientist at Imperial College London." 

This is among the bleakest U.N. climate reports I have read. It carries the unmistakable tone of desperation, frustration and urgency - but not resignation," said Andrew Weaver, a climate scientist at the University of Victoria."

Making the temperature of the world go down is a lot harder than making it go up.  

Wapo again:

"That's because it is far more difficult to take carbon out of the atmosphere that it is to release it, said Joeri Rogelj, a climate scientist at Imperial College London and another lead author of the report."

We could plant million, or billions of trees to absorb carbon from the air. But those trees have to be planted somewhere.  Probably partly on agricultural land that should be used for food.  Then, if there's a forest fire, a big chunk of carbon absorption would be wiped out in a day.

We could build machines to suck carbon out of the air and store it underground. But we do not yet have the technology, or the money to do this on a large enough scale.  

For now, the world will keep warming. Maybe we'll get a temporary, semi-break around 2028 when El Nino ends and the Earth's temperature might go down marginally. But that will only be a blip, and the world will keep warming until humanity can get its act together. 

Since humanity has never truly gotten its act together, I'm not terribly optimist

More Quiet Vermont Weather, "Popcorn" Showers Are Over, Sunshine To Win

Changeable skies over St. Albans, Vermont on Saturday. 
It rained a little five minutes before and 10 minutes 
after this photo was taken. It was about as
changeable a day as you can get. It should
turn much sunnier by this afternoon. 

 We got through a very changeable Saturday, didn't we?  

Sun, light rain, sun, clouds, wind, light rain, every minute was different. Life in Vermont, I guess. The rain didn't amount to anything. If you got the showers, you received a trace to a few hundredths of an inch of rain. So the light showers didn't exactly wet things down. 

All that Saturday keep-on-your-toes weather came from an old storm in the Maritime Provinces of Canada is departing. Good for them, as the system caused severe flooding around Cape Breton, Nova Scotia.

TODAY

It was still cloudy, with areas of fog early this morning, a typical state of affairs for an early morning in September. The fog should lift by mid-morning, as usual. The clouds might take a little longer, especially in southern Vermont.

One last disturbance spawned by that Maritime Provinces moving south through New England produced a few early showers, especially in southern Vermont. That's heading south. Clouds and perhaps a very light showers might linger for a time south. 

But eventually, the sun will come out, and forecasters are insisting it will be a sunny, pleasant afternoon. Still a little on the cool side, with highs within a few degrees either side of 70 degrees.

Tonight will be among the coolest nights of the season so far, as we continue to sink into the autumn. Lows will be in the 40s in most places, with low 50s again in the Champlain Valley. 

LABOR DAY

A very nice day to unofficially end summer. After that cool start we should get well  into the 70s under sunny skies. Enjoy the outside

TUESDAY

Back to school, back to work. Under generally sunny skies once again, we should get right back in the 70s for highs. An incredibly lame weather disturbance from Quebec could spread a few clouds in during the day. but that won't disturb our stretch of good weather. 

WEDNESDAY

Our best shot at some needed rain. Yet another cold front will come at us. It will be able to grab just a bit of moisture from that horrible hot, humid air far to our south and bring it our way. As south winds pick up, you'll feel the day starting to turn a little more sticky. Showers should arrive  in the afternoon and last through the night, as it looks now. 

It's a little early to know how much rain we'll get, but early guesses are we could get a half inch or so, Maybe. We'll take anything we can get. It's still dry out there

It's also still early enough to expect some changes in the forecast for the timing and the amount of rain. 

THURSDAY/FRIDAY

It'll cool down again, as it almost always does after a cold front goes by. Originally, it looked like this next shot would have been our first chance of frost of the season. Even then that frost would have been only in the very coldest hollows.

Lately, computer models have been backing off on the how cool the air might get.  So, our early guesses will be highs back down near 70 and lows in the 40s. Typical September weather. 

Quiet Vermont Weather Week During What Is Usually Quietest Weather Month Of Year. On Bright Side, No Hurricanes, As In Past Septembers

Damage in Brattleboro, Vermont after the Great 
New England Hurricane of 1938. This year is an
incredibly quiet Atlantic hurricane season, thanks to
El Nino. However, in the past, Septembers have
brought destructive tropical storms to Vermont.

The weather in and around Vermont is quiet, and will mostly remain on the quiet side for the next week. It's a nice contrast to the record heat and destructive storms elsewhere in United States lately.  

This is the time of year when large high pressure systems drift into New England from southern Canada. It's true this year, even with a stuck weather pattern that has kept the south central U.S. broiling since July, and has kept the severe weather in the Great Lakes/Mid-Atlantic states for the past several weeks.

It seems like the almost the only extreme weather Vermont sees in September is dying hurricanes, which can cause severe flooding and a lot of wind damage.

Not this year, of course. Incredibly, the National Hurricane Center sees no signs of tropical storms forming in the Atlantic Ocean for the next seven days. That's an absolutely wild thing to say at the peak of hurricane season.  El Nino is really doing its job at suppressing Atlantic hurricanes. 

In the past, of course, hurricanes and tropical storms have really tormented Vermont in past Septembers.

Great New England Hurricane

The biggest one, of course, was the Great New England Hurricane in 1938, killing nearly 700 people After coming ashore on Long Island and Connecticut, the 1938 hurricane quickly reached Brattleboro then curved northwestward toward Burlington. 

Especially along and east of that track, winds leveled forest across Vermont. Here's one example from the Vermont Weather Book: The hurricane destroyed 2,400 of 3,500 trees in a sugarbush in Cabot. And as we all know, it takes a long time to grow new trees, so this storm was incredibly devastating. 

The western side of a hurricane is especially rainy. We had a lot of rain in the days leading up to the hurricane, so the torrential rains  from the storm caused extensive flooding, some of the worst on record in Vermont. 

It was a rough stretch for floods in Vermont. Our worst flood on record hit in 1927, as most Vermonters know. A terrible destructive flood hit in 1936, then we had the great hurricane of 1938. Three mega-floods within 11 years.

We've had more recent tropical storms, of course. I"m omitting storms like Tropical Storm Irene in 2011, because that one hit in August. I'm only discussing September storms here.

David/Frederick, 1979

In 1979, two ex-tropical storms pestered Vermont in September. Ex-Hurricane David, having killed 2,000 in the Caribbean, swept up the East Coast from Florida to New England. The center of the now-former hurricane crossed Vermont on roughly a Danby to Thetford path. 

The storm brought heavy rain, damaging winds and a possible tornado that took part of the roof off a new supermarket in West Rutland 

A week later, ex-hurricane Frederick, which had devastated parts of the Gulf Coast, crossed northwest Vermont with more wind and rain statewide. A possible a collapsed a covered bridge between South Newbury, Vermont and Haverhill, New Hampshire. 

Floyd, 1999

We were damn lucky Vermont was having a serious drought in the weeks leading up to ex-hurricane Floyd in 1999. It slammed into North Carolina and at the time became the most expensive hurricane in that state's history. 

The weakening hurricane continued on up the East Coast, coming across Vermont on September 16-17. Three to seven inches of rain fell, with locally higher amounts. This would have caused severe flooding, except that severe drought meant water levels were extremely low before the storm. .

Still, flooding hit. The Tunbridge World's Fair had to be canceled due to high water A section of Route 5 in Weathersfield was washed away, One person died when high winds blew a tree down on them 

Next Few Days

We're definitely not going to have a tropical storm in the next few days. All in all, it will be a nice Labor Day weekend 

Today: Partly cloudy, a chance of widely scattered light showers Highs in the 70s

Sunday/Monday: Sunshine, with daytime highs in the 70s. The only major clouds would be patchy dense fog in the river valleys both mornings. That'll burn off by mid-morning 

The next chance of rain will come along probably on Wednesday and Thursday. So far, rainfall amounts with this thing don't' look like they'll be that impressive.