Although there will be more brutal heat to come, summer is over and fall is here, according to the climatological calendar. June through August will enter the record books as abnormally hot for a considerable portion of the Lower 48 states.

Large parts of the western United States notched their hottest summer on record, including Phoenix and Las Vegas. Hot weather frequently visited both coasts and scorched the northern and southern borders.

Below, we recap six of the most notable aspects of yet another historically hot summer in the United States.

Heat waves every week

Intense heat domes sprawled across portions of the nation every week.

The most memorable heat wave ramped up around Independence Day in the West and brought all-time highs on multiple days, including in Las Vegas and Redding, Calif. It featured nine days in a row with highs of at least 120 degrees in the Southwest, with a maximum of 129 on July 7 in Death Valley, Calif. — among the hottest days ever observed at the world’s hot spot.

Overall, about a dozen heat waves affected the nation. South Texas saw extreme heat as early as May, when temperatures surpassed 115 degrees.

Punishing heat on both coasts

Many dozens of cities in the West, Northeast and Gulf Coast posted their hottest summer on record (as measured by average temperature for the three-month period). California and Arizona had the most locations with record-hot summers.

Far-flung cities that notched their hottest summers included:

• Phoenix: Average temperature of 98.9 degrees

• Fort Lauderdale: 84.6

• Redding, Calif.: 84.4

• Grand Junction, Colo.: 80.1

• Dulles, Va.: 78.1

• Reno: 77.5

• Hartford, Conn.: 75.5

• Flagstaff, Ariz.: 68.4

• Caribou, Maine: 67.3

Others had their second-hottest summer, including Denver; Amarillo, Texas; Mobile, Ala.; and Daytona Beach, Fla.

Overall, more than 200 cities and towns with long-term weather records observed one of their hottest five summers.

The nation’s hottest cities had their hottest summer

Phoenix and Las Vegas are the hottest big cities in the country. Both witnessed record hot summers, and little relief is in the forecast as fall settles in.

When Phoenix registered its hottest summer on record in 2023, it was improbable that it would top that record one year later. Yet somehow 2024 was even hotter.

Its summer average of 98.9 degrees outdid 2023’s average of 97 by nearly two degrees. It’s in the midst of a record-long streak with days reaching 100 degrees.

Las Vegas had its hottest summer on record by an enormous margin, topping 2018 — the next-hottest summer — by 2.5 degrees. Its average temperature of 96.2 degrees included 12 calendar-day record highs and an all-time high of 120 on July 7.

Other hot locations in the region had their hottest summer, including:

• Death Valley, where an average temperature of 104.5 degrees topped 104.2 in 2021.

• Palm Springs, where 96.2 topped 95.3 in 2021.

• Yuma, Ariz., where 95.7 topped 95.3 in 1994.

All-time records galore

Las Vegas was one of many cities that posted their hottest day on record this summer, especially in the West.

All-time highs were set in more than 250 locations across the Lower 48 states. Some of the most noteworthy all-time highs are listed below:

• 124 in Palm Springs, Calif., on July 5

• 120 in Las Vegas on July 7

• 119 in Redding on July 6

• 117 in Ukiah, Calif., on July 6

• 115 in Palmdale and Lancaster, Calif., on July 7 and July 6

• 114 in Fresno, Calif., July 7

• 106 in Ogden, Utah, on July 12

Outside of the West, there were plenty more:

• 115 in Medicine Lodge, Kan., on Aug. 24

• 113 in Abilene, Texas, on Aug. 21

• 109 in Williston, N.D., on July 25

• 106 in Raleigh, N.C., on July 5

• 102 in Hagerstown, Md., on July 16

• 96 in Caribou, Maine, on June 19

Record heat from border to border

Abnormally high temperatures expanded to both the northern and southern borders of the United States. The summer average of 67.3 degrees in Caribou, Maine, surpassed 2020’s previous high mark of 66.9.

About 2,600 miles to the southwest, in between Phoenix and Los Angeles, the dusty border city of Yuma, Ariz., averaged 95.7 degrees, a record high. It reached at least 100 on 91 out of 92 days from June through August, which is about two weeks more than normal.

Summer maximums of 100 to 105 were common from Washington state to North Dakota and also visited northern New England.

Unforgiving heat and humidity in Florida

Although the Sunshine State saw heat and humidity less extreme than the summer before, the persistence of muggy weather was exceptional. July was its most painful month. Fort Lauderdale and Orlando notched their hottest Julys on record, while the month ranked among the top five hottest in most other places.

For the summer overall, Tallahassee, Fort Lauderdale and Punta Gorda posted a record-hot season, with most other spots ranking in the top five.

The soupy weather was fueled by much warmer-than-normal water temperatures.

The peninsula is projected to continue running warmer than normal through the fall.