Climate Matters•September 21, 2022
Summer 2022 in Review
Hazardous heat waves, historic rainfall, devastating flash floods, wildfires, and persistent drought. Summer (June-August) of 2022 was a season of extremes.
Summer 2022 was the third hottest on record for the U.S. Over 100 U.S. cities experienced one of their top-ten hottest summers this year.
Climate Central’s new Climate Shift Index has detected a strong influence of climate change on summer temperatures across much of the U.S.
In 2022, nearly half (49%) of the contiguous U.S. (equivalent to 132 million people) experienced 15+ summer days with average temperatures made at least twice as likely due to climate change.
For 64% of the contiguous U.S. (or 72% of the population), minimum (nighttime) temperatures were made at least twice as likely due to climate change on 15 or more summer nights in 2022.
Summer 2022: record heat across the U.S.
Summer temperatures were much above average for most of the Lower 48 states. In 2022, Texas, Massachusetts and Rhode Island all experienced their second-warmest summers since 1895. And seven other states experienced one of their top five warmest summers since 1895: New Hampshire, Connecticut, New Jersey, Louisiana, California, Oregon, and Washington.
Gauging summer 2022: record heat in cities
Climate Central ranked summer average temperatures in 239 U.S. locations, each having a different starting year (ranging from 1863 to 1981) for their period of record (see methodology). Based on this analysis:
Five cities had their hottest summer on record in 2022: Bryan, Texas; Cheyenne, Wyo.; Salt Lake City, Utah; San Antonio, Texas; and Tampa, Fla.
Summer 2022 was among the top five hottest on record for nearly a quarter (52) of locations.
107 locations experienced one of their top-10 hottest summers on record in 2022.
Was it climate change?
Our warming climate is making heat extremes more likely (see Climate Central’s Extreme Heat Toolkit). But how did climate change influence the summer heat we experienced in 2022? New Climate Central analysis using the Climate Shift Index (CSI) offers some answers.
Launched earlier this year, the CSI shows the local influence of climate change on daily temperatures. A CSI level of +2 means that climate change made exceptionally warm daily temperatures for a given location at least twice as likely.
In 2022, nearly half (49%) of the contiguous U.S. experienced 15 or more summer days with average temperatures that were made at least twice as likely due to climate change.
In other words, over 132 million people across the contiguous U.S. (about 40% of the population) experienced a strong influence of climate change on average temperatures for at least two weeks (15+ days) of the summer.
Much of Nevada (including Las Vegas), southern Texas (including San Antonio and Houston), and southern Florida (including Orlando and Miami) had 50 or more summer days with average temperatures that were at least twice as likely due to climate change.
And in the area around Tampa, Fla., more than 70 summer days had average temperatures that were at least twice as likely due to climate change.
Climate fingerprints on summer nights
Since records began in 1895, summer minimum (nighttime) temperatures across the U.S. have warmed at a rate of +1.6°F per century—nearly twice as fast as the warming rate for summer maximum (daytime) temperatures.
In 2022, the contiguous U.S. experienced its second-warmest summer minimum (nighttime) temperatures on record (since 1895). 66% of the contiguous U.S. (by area) was affected by extremely warm summer nights, compared to 27% exposed to extremely warm days. And August nighttime temperatures were the warmest on record (since 1895) for California, Oregon, Washington, Nevada and Idaho.
So how did climate change influence the sweltering summer nights we experienced in 2022?
In 2022, 64% of the contiguous U.S. (or 72% of the population) experienced 15 or more summer nights with minimum temperatures that were made at least twice as likely due to climate change.
For much of Nevada (including Las Vegas), southern California, western Arizona, southern and eastern Texas (including Houston and Dallas), and most of Louisiana and Florida, at least 50 summer nights had temperatures that were made at least twice as likely due to climate change.
And most of southern and central Florida and parts of southern Texas experienced 70 or more summer nighttime temperatures made at least twice as likely due to climate change.
POTENTIAL LOCAL STORY ANGLES
For more local summer temperature and precipitation rankings:
NOAA Climate at a Glance for summer temperature and precipitation rankings, maps, and time series plots at national, regional, state, and city levels.
Summer 2022 extremes weren’t only about the heat. What were some other notable U.S. events?
Heavy Rain and Flooding: Because a warmer atmosphere can hold more moisture, climate change is increasing the frequency of extreme precipitation (see Climate Central’s Heavy Rain and Flooding Toolkit). In late July 2022, a stalled frontal system brought extreme rainfall and catastrophic flash flooding to parts of Missouri and eastern Kentucky, resulting in fatalities and extensive damage. During August, “1,000-year” rainfall events drenched parts of southern Illinois and brought historical rainfall, flash flooding and damage to Death Valley National Park and parts of Dallas, Texas.
Wildfire: Warm, dry, windy conditions make fires more likely (see Climate Central’s Wildfire Toolkit). In 2022, wildfires were active in parts of the South and Southwest, in Alaska through June and July, and across the West and southern Plains. As of September 15, over 50,600 wildfires have burned more than 6.7 million acres this year (above the 10-year average), impacting ecosystems, property, and air quality. InciWeb’s national maps can be used to monitor current fire incidents.
Drought: Rising global temperatures are altering the water cycle and increasing the risk of drought in parts of the U.S. (see Climate Central’s Drought Toolkit). A recent study indicates that the ongoing southwestern megadrought (since 2000) is the most severe of the past 1,200 years. As of August 30, 45.5% of the contiguous U.S. was in drought—a decrease from the summer peak of 51.9% on July 26. In August, severe to exceptional drought was widespread from the Great Basin to the Pacific Coast, across portions of the central and southern Plains, and in parts of New England. By August 30, a record 94% of the state of Hawaii was affected by drought. And in July, Puerto Rico experienced a record 85 consecutive weeks of drought.
Hurricanes: Warming oceans are fueling stronger tropical cyclones (see Climate Central’s Tropical Cyclones Toolkit). Despite predictions for an above-average Atlantic hurricane season due to the ongoing La Niña, there were only three named storms during the summer. However, fall is often the most active season for tropical storms and hurricanes, and Hurricane Fiona brought heavy rainfall, high winds, catastrophic flooding, and widespread blackouts across Puerto Rico before making a second landfall in the Dominican Republic on September 19.
The SciLine service, 500 Women Scientists or the press offices of local universities may be able to connect you with local scientists who have expertise on summer extremes and climate change. The American Association of State Climatologists is a professional scientific organization composed of all state climatologists.
Kristina Dahl, PhD
Principal Climate Scientist
Union of Concerned Scientists
Media contact: firstname.lastname@example.org
Related expertise: Impacts of extreme heat
Jorge E. Gonzalez Cruz, PhD
SUNY Empire Professor of Atmospheric Sciences
University of Albany
Related expertise: urban climate and weather
*Available for interviews in English and Spanish
Luis E. Ortiz, PhD
Department of Atmospheric, Oceanic, and Earth Sciences
George Mason University
Related expertise: urban heatwaves
*Available for interviews in English and Spanish
To calculate average CSI data, the non-rounded version of CSI (called the Climate Factor, or CF) associated with minimum and maximum daily temperatures was collected using Climate Central’s Climate Shift Index methodology from June 1 to August 31, 2022. The daily minimum and maximum temperature CF were then averaged, then converted to CSI, and aggregated to Designated Market Areas (DMAs). The number of days with an average CSI greater than or equal to 2 for each DMA was then calculated.
Annual average summer (June–August) temperatures were obtained for each year of a station’s period of record using data from the Applied Climate Information System and were subsequently ranked. The period of record varies by station. Local graphics were not produced for eight stations due to missing daily data that could potentially impact this year's ranking, including: Albany, Ga.; Idaho Falls and Twin Falls, Idaho; Presque Isle, Maine; Greenville, Miss.; Glendive, Mont.; Manchester, N.H.; and Bend, Ore.