Maps show where extreme heat shattered 7,000 records this summer

It was the summer that wouldn’t quit. From early June to straight past Labor Day, waves upon waves of heat scorched and baked the country, smashing thousands of temperature records along the way.

And summer may have saved its worst for last: Oppressive heat in the West that finally broke Saturday set hundreds of records on its own. Meteorologists described it as the most extreme September heat wave ever observed in the Western United States.

Broken temperature records,
June 1 through Sept. 7

More than 7,000 daily temperature records across the United States were broken this summer, a Washington Post analysis of data from the National Oceanic and Atmospheric Administration revealed. In the third-hottest summer on record, more than 400 monthly records and 27 all-time records also fell.

Daily temperature records, meaning the highest temperature ever recorded at a particular station on a particular calendar date, are broken more frequently than monthly records, which indicate the highest temperature ever recorded during a whole month. Breaking all-time records — the hottest temperature recorded at a station in its entire history — is even rarer.

Such records are but one measure for tracking and quantifying summer heat. Other metrics can offer a longer-term perspective, such as a location’s summer average temperature over time.

Taken together, the records show a country coping with hotter days that fuel larger forest fires and longer, more intense droughts.

Tens of thousands of weather stations across the United States, from big cities to small towns, in deserts and on mountain slopes, feed data to NOAA’s daily temperature database. Of those stations, some 7,600 have at least 30 years’ worth of daily temperature data, enough for scientists to draw long-term conclusions about climate changes. The Washington Post analyzed those stations to discover where and when records had been broken from June 1 through Sept. 7.

[Heat-wave map: See where Americans face the most extreme heat risk]

Heat fell upon the country in waves, causing a spate of record-breaking temperatures across the Southwest in June, wildfires that scorched Northern California and the Pacific Northwest in July, and destruction to Midwestern farms in August, culminating in a barrage of sweltering days across the West in early September.


Amid a June heat wave that roasted the Southwest, the weather station in Tucumcari, N.M., population 4,872, recorded an all-time high of 112 degrees on June 11.

“It was pretty brutal,” said Ron Warnick, the lone full-time reporter at the Quay County Sun, Tucumcari’s weekly newspaper. To make matters worse, the town had to close its swimming pool because of a leak, and decades of drought have long since dried up Tucumcari Lake.

[London hit 104 degrees. That’s like 128 degrees in Las Vegas.]

“Folks here generally handle the heat well, but I heard people complaining who are lifers in Tucumcari,” Warnick said. Even his dogs refused to play outside.

The all-time high in Tucumcari was among scores of heat extremes across the country in mid-June. Daily records first were set in Phoenix, Las Vegas and Salt Lake City, while Denver hit 100 degrees on June 11, tying its record for the earliest day the city hit triple digits.

As the heat wave crept east, it set records from Texas to Wisconsin. St. Louis recorded its warmest June night on record, and Milwaukee posted its highest June heat index, a measure of how hot it feels factoring in humidity, in 48 years: 109 degrees.

Late June brought searing temperatures to the Southeast, with daily record highs being set from New Orleans to Raleigh.


July’s most widespread unusual heat occurred mid-to-late month, when searing temperatures set records in the West and South. Salt Lake City tied its all-time high of 107 degrees, while Oklahoma City soared to 110, its highest July temperature on record.

As Texas registered its hottest July on record, Houston hit 105 on the 10th, matching its highest temperature ever observed during the month. Austin soared to 110 the same day, establishing a July record.

To conclude July, a prolonged heat wave in Northern California and the Pacific Northwest set records for the longest streaks with highs at or above 90 and 95 degrees in Portland and Seattle, respectively. Medford, Ore., posted a high of 115 on July 29, tying its highest temperature in 111 years.

Amid this heat wave in the Northwest, a forest fire ignited on July 29 near McKinney Creek Road, by the Klamath River in Northern California. The McKinney Fire would grow into California’s largest and deadliest fire of the year to date.

That day, about 55 miles to the southeast, a weather station on a mountain slope near Dunsmuir, Calif., recorded an all-time high of 106 degrees. Dunsmuir’s mayor, Matthew Bryan, thought that sounded low. His thermometer hit 111, he remembered.

The wind patterns kept the McKinney Fire from threatening Dunsmuir, but the town, situated at the bottom of a canyon, is uncommonly vulnerable to fires. In recent years, Western wildfires have become hotter and less predictable. Bryan said he worries that Dunsmuir could become the next Paradise, the California town that was almost completely destroyed by the Camp Fire in 2018.

“It’s an existential crisis,” Bryan said. “It’s not as if we can do anything this week, this month or this year that’s going to really stop the threat.”


August kicked off with an oppressively hot and humid air mass over the Plains. On Aug. 1, Des Moines posted a low of just 82 degrees, its warmest low temperature since 1936. Meteorologists said “corn sweat,” or the moisture exhaled into the atmosphere by the crop, intensified the humidity.

The weather station in Bridgewater, S.D., a farming town of 511 people, recorded an all-time high of 107 degrees on Aug. 3.

“That first week of August was a bugger,” said Lyndon Hofer, a farmer who lives six miles south of Bridgewater. “I believe it probably broke records all around.”

Hofer grows corn and soybeans. In normal summers, he gets between 160 and 180 bushels of corn per acre. The drought and heat wave slashed his yields by more than three-quarters. Many acres grew nothing at all. Crop insurance covered his expenses, but he made no profit this year.

When you get the two thrown together, extremely high temperatures and then no moisture, well, it just takes a matter of a few weeks and everything burns up,” Hofer said.

In his five decades of farming, Hofer has noticed the weather upon which his livelihood depends has changed. “When it’s dry, it gets drier. When it’s cold, it gets colder. When it’s hot, it gets hotter,” he said. “If somebody asked my opinion, I’m not a big believer in climate change. But weather does seem to be getting more extreme.”

America is on pace for its lowest corn yield since the drought of 2012, according to analysts at Rabobank, which collects data about commodity markets. Yields in all crops could be down by as much as a third compared with last year, according to the American Farm Bureau.

The Northeast emerged as the other hot spot in early August. Boston saw six straight days at or above 95 degrees between Aug. 4 and 9, its second-longest such stretch, capping the city’s hottest 30-day period on record. The heat was made worse by severe drought in the region at the time. Massachusetts was among five states in the Northeast to have its warmest August on record.


The heat wave that gripped California and other parts of the West for more than a week was the most severe ever recorded in September, weather experts said, confirming what California Gov. Gavin Newsom (D) called the “hottest and longest on record” for the month.

On Sept. 7, a temperature station in Calistoga, Calif., a town of 5,346 people, hit 118 degrees.

Nearly 300 weather stations recorded their hottest September temperatures ever. Salt Lake City, Sacramento and Reno, Nev., broke their September records multiple times and by large margins.

It was the “greatest September heat wave ever west of the Rockies hands down,” tweeted weather historian Maximiliano Herrera on Wednesday.

What temperature records say about climate change

In a stable climate, temperatures bob back and forth like a seesaw, equally likely to break high records as low ones. But in a warming world like ours, the seesaw is weighted toward the high side.

Over the past two decades of summers, far more record highs have been broken than record lows. This summer, more than three times as many high records were broken than low ones.

Highs and lows
Number of daily record highs and record lows broken from June 1 to Sept. 7, 2000-2022
Hover to see the numbers for each year

Without climate change, the orange bars and the blue bars in the chart above would balance each other out. In about half of the years, the blue bars would be longer; in the other half, the orange bars would be longer.

But in 19 out of the 23 summers since the year 2000, more record highs have been broken than record lows, so the orange bars are almost always bigger than their blue counterparts.

Dylan Moriarty contributed to this report.

About this story

Daily temperature records were downloaded from NOAA’s Global Historical Climatology Network daily (GHCNd) database. A daily record indicates the extreme (highest or lowest) temperature at a particular weather station on a given date. Monthly records indicate the extreme temperature at a station for a whole month, and an all-time record indicates the extreme temperature ever recorded at the station. The analysis includes only those weather stations that have at least 30 years’ worth of data, each of which with at least 182 days of recordings, the standard used by NOAA.

Shaded relief data was downloaded from Natural Earth.