What does it take to hit 100? The long road to triple-digit heat in U.S. cities
Tampa recently marked its first 100-degree day since 1890.
During heat waves, the urban heat island effect is more intense and lasts longer.
On Sunday, July 27, Tampa, Florida, made history by hitting 100 degrees for the first time since record-keeping began in 1890. A day later, the thermometer at Tampa International Airport topped out at 95 degrees in the afternoon, a narrow miss for a second consecutive day of triple-digit heat. For Northern dwellers who dream of sunshine and beaches in the dead of winter, and even Floridians who boast about their heat hardiness, the fact that a Florida city had never officially reached 100 degrees came as a surprise—and for many, disbelief.
Part of the reason for Tampa's atypical leap across the century mark is due to wind direction. For Tampa’s scorcher, winds came out of the north and northeast, bringing dry air off the land with no cooling onshore breezes from the water, explained AccuWeather Senior Meteorologist Alan Reppert. "That is what helped to keep the air warmer and not allow it to get any cooling from the water," he added.
In 2025, every state in the continental U.S. has recorded a temperature over 100 degrees at a weather station, except for Wisconsin, Michigan, Vermont, Illinois, Indiana and Ohio.
Besides Tampa, what about the climate identities of other American cities from coast to coast? And why do some places like Phoenix and El Paso rack up thousands of triple-digit days while others like San Francisco or Portland barely hit that mark once a decade? What does it really take to hit 100 degrees?
West Coast
Los Angeles, California: 71 days
Sunny Los Angeles, and Southern California more broadly, is often hailed as having one of the best climates not only in the U.S., but anywhere in the world. That reputation owes a lot to geography: much of the population lives near the coast, where the cooling influence of the Pacific Ocean makes all the difference.
California is a state of microclimates, where it can be comfortable at the coasts, warm in the valleys and downright scorching in the deserts. Los Angeles gets plenty warm in the summer, but piping hot heat waves are usually confined to August, September and sometimes October, when the Santa Ana winds eventually kick in.
Sunrise over West Hollywood with the downtown skyline of Los Angeles in the background. (Photo credit: Getty Images)
Los Angeles has reached the century mark just 71 times in Downtown Los Angeles between 1906 and 2025, according to available NOAA records. In 1939, Los Angeles hit 100F seven times, a record for the city. That notable year also saw the 1939 Long Beach tropical storm, aka "El Cordonazo," strike the port city of San Pedro, causing torrential rains and flooding in late September. For contrast, Palm Springs, just a two-hour drive inland, has reached 100 degrees nearly 11,500 times. So next time you're enjoying a mild L.A. afternoon in July, thank the Pacific. Even the stars do.
Phoenix, Arizona: 11,410 days
Palm Springs is part of the Sonoran Desert, as is Phoenix. OK, it's not exactly a surprise that the city aptly known as the Valley of the Sun is very hot, but there is a brief period in early winter where Los Angeles actually averages slightly warmer high temperatures. But then Phoenix leapfrogs past the City of Angels and every major U.S. city for a total of 11,410 days of 100 F or more since the early 1900s. If you want to up the ante to days of 110 F or more, Phoenix still delivers the heat, with more than 1,800 days.
Cactus in the desert of Piestawa Peak hiking zone in Phoenix, Arizona. (Photo credit: Getty Images)
In the nearby Mojave Desert, Las Vegas has recorded around 8,750 days past the century mark, a slightly lower number than Phoenix due in part to the Sin City's higher latitude and elevation. Topography also comes into play. Phoenix sits in a location that allows for the air to come from the south and retain heat, said Reppert, rather than be affected by any water or air coming up a mountain into the area like Las Vegas has.
Seattle, Washington: 6 days
Seattle is known for cool, cloudy, and damp weather, similar to London or Amsterdam, so it’s not surprising that the city has recorded just six 100-degree days over the years. However, just a two-hour drive east, across the Cascade Mountains, tells a very different story. The town of Yakima has logged a scorching 595 triple-digit days, a striking example of the dramatic climate shifts that define the West Coast. In 2015 alone, Yakima experienced 24 days at or above 100 F.
Honolulu, Hawaii: 0 days
Believe it or not, Hawaii holds a unique distinction: It’s the only U.S. state to have never recorded a high of 100F or more and also the only one that has never dipped below zero F. Extreme weather records for the state have indicated that the small town of Pahala hit the century mark in 1931, though other meteorologists have disputed that number. But when it comes to warm days, Honolulu doesn’t disappoint. In 1928, every single day of the year, yes, all 366 of them thanks to a leap year, hit at least 80 F in Honolulu. A hui hou — until we meet again.
Mountain West and Midwest
Denver: 90 days
Even though the Mile High City gets plenty cold in the winter, the city looks a lot different in the summer. Known for its large diurnal (day and night) temperature swings, Denver has hit the elusive 100 F mark 90 times since the early 1920s. 2012 was a scorcher summer, with 13 days above the century mark. Notably, 2023 saw zero days at 100 F or above.
Salt Lake City: 578 days
Skyline of Salt Lake City with the LDS temple in front of the Wasatch Mountain Range on a sunny summer day. (Photo credit: Getty Images)
Salt Lake City is another high-elevation city that experiences surprisingly hot summers. Since the late 1920s, it's reached 100 F a total of 578 times. In 2022 alone, the city broke records with 86 days hitting 90 F or higher, and 34 days at or above 100 F. And just to show how wild the swings can be, in 1966 the last freeze came almost in June.
Chicago: 71 days
While not known for scorching heat, Chicago has still seen its fair share of triple-digit days — 71 since 1901. The Windy City is more famous for lakefront breezes and brutal winters, but when the heat dome settles in, it can get real. Summers here can be sneaky-hot, with heat indices pushing well past 100 even if the thermometer says otherwise. Still, compared to cities in the West or South, hitting that 100 F mark remains relatively rare, which makes those few sweltering days all the more memorable. During the Dust Bowl years, Chicago Midway Airport recorded a record eight consecutive 100 F+ days in July 1936.
Minneapolis: 64 days
Minneapolis may be known for its icy winters and snow-packed streets, but since 1901, the city has recorded 64 days at or above 100 F, a reminder that the Upper Midwest can bring the heat, too. Long summer days and occasional heat waves off the plains can push temps into triple digits, even if it’s not the norm.
South
Oklahoma City: 1,580 days
Oklahoma City might be best known for its spot in Tornado Alley and its history of intense droughts, but the heat here deserves its own headline. Since 1901, OKC has recorded a blistering 1,580 days of 100 F or higher — making it one of the hottest cities in the country by this metric. The summer of 2011 was especially brutal, with 63 days hitting triple digits. Days with temperatures exceeding 110 F are not out of the question in this climate.
Miami: 1 day
Ocean Drive on a sunny morning, Miami Beach, Florida. (Photo credit: Getty Images)
Despite its steamy reputation, Miami hasn't seen that many days above the century mark. In 1942, a Miami airport logged 100 F. Miami Municipal Airport is now the site of Amelia Earhart Park. However, don’t be fooled by the lack of triple digits. The tropical city has logged more than 6,600 days at or above 90 F since the early 1930s, making scorching summer days more of a norm than a novelty.
Topical locations have a tough time to get to 100 degrees due to not only being along the water, but all the moisture that the winds pick up from the water, said Reppert. "With more water in the air and needing to heat the moisture and the air, it's much tougher to get temperatures of 100 degrees or higher," he explained. "Unless the water is in the Arabian Gulf and already with water temperatures well into the 90s, it's tough to get locations with water temperatures lower than that to climb to 100 degrees."
New Orleans: 54 days
The Big Easy has officially hit 100 F just 54 times since the early 20th century — a relatively modest number given its famously muggy summers. And despite a warming trend across much of the country, New Orleans hasn’t seen a single 100-degree day in either 2024 or (so far) 2025.
Houston: 325 days
Houston may be better known for hurricanes and the Astros, but it’s no stranger to serious heat. Since the early 1900s, the city has logged 325 days at or above 100 F. While it doesn't rival Texas heat champs like Dallas (more than 2270) or Austin (more than 1680), Houston’s combo of high temps and suffocating humidity makes those triple-digit days feel especially intense.
Northeast
The sun rises behind the skyline of midtown Manhattan and the Empire State Building in New York City, on June 19, 2025. (Photo by Gary Hershorn/Getty Images)
New York City: 60 days
The Big Apple may not be known for desert heat, but it’s hit 100 F or higher 60 times since the early 1900s. That said, it’s been a while — the last triple-digit day in the city was back in 2012. With dense urban heat and humidity, even high 90s can feel unbearable across the five boroughs from June through August.
Boston: 26 days
In a twist worthy of the Beantown–Big Apple rivalry, Boston has reached 100 F 26 times, including in 2025, while New York City hasn’t done so since 2012. The New England city hit 102 degrees on June 24, breaking the record for the hottest June day in history. Just another way these two cities keep trying to one-up each other, even when it comes to extreme heat.
Washington, D.C.: 112 days
The nation's capital doesn’t just bring the political heat, it brings the real kind, too. Washington, D.C., has recorded 112 days of 100 F or higher since the early 1900s. Summers here are notoriously hot and humid, and when the temperature spikes, the swampy nickname starts to feel a little too on point.
Philadelphia: 62 days
Rounding out the Northeast corridor, the City of Brotherly Love has logged 62 days of 100 F heat since the early 1900s. While not known for extreme highs, Philly has seen its share of scorching milestones—especially during historic heat waves like those in 1988 (the most 100 F days in a year with five) and 2011, which recorded the highest low on July 23 of 83 F.
You might wonder how Chicago was able to leapfrog past the Big Apple and the City of Brotherly Love when it comes to 100-degree days. Reppert explained that Philly, much like New York City, can be influenced by the water nearby and any south or east wind direction can bring much cooler air off the Atlantic, which normally peaks in the lower 70s near both of the cities.
In Chicago, winds from the south or west come off the land and can be much warmer. "Even with Chicago having Lake Michigan, most of the warm wind directions for that city will not be influenced by the lake," he said.
