PHILADELPHIA — Nearly two-thirds of the American public say climate change is increasing the risk of respiratory diseases and heat- and insect-related illnesses, according to a new survey from the Annenberg Public Policy Center (APPC) of the University of Pennsylvania.
In September 2026, the U.S. National Oceanic and Atmospheric Administration (NOAA) announced that the past summer, from June through August, had been the warmest in the lower contiguous 48 states in the 132 years in which records have been kept. The United Nations reported that global sea surface temperatures had "reached an all-time observed high."
The policy center's nationally representative Annenberg Science and Public Health (ASAPH) survey, which was conducted Aug. 4-17, 2026, among 1,904 empaneled U.S. adults, finds that 76% report that extreme outdoor heat affected their daily activities at least sometimes in the past year and 38% say poor air quality resulting from wildfire smoke did so. The American Lung Association's "State of the Air" 2026 report found that 44% of Americans are living in areas that earn "failing grades for unhealthy levels of ozone or particle pollution."
Extreme heat is affecting the everyday lives of most Americans, the survey finds. (Download the topline .)
"Extreme heat is no longer just an occasional inconvenience," said Ken Winneg , APPC's managing director of survey research. "It is affecting Americans' household budgets and daily routines, from electricity bills to simply going outside."
Most recognize climate change's health risks
Nearly two-thirds of Americans (65%) say that climate change is increasing the risk of heat-related illnesses, respiratory diseases, and insect-borne diseases. This is unchanged from August 2025 (65%) and July 2024 (67%) but is significantly higher than 58% in November 2023.
Americans generally recognize that heat waves are on the rise. Nearly two-thirds (62%) say U.S. heat waves are becoming more frequent and intense than in the past, statistically unchanged from 61% in August 2025, 65% in July 2024, and 58% in November 2023.
Of the four extreme weather events measured in the survey, more Americans report that their daily activities were impacted at least sometimes by extreme outdoor heat (76%) and poor air quality resulting from wildfire smoke (38%). As one would expect, fewer say they were impacted at least sometimes by flooding (20%) and tornadoes/hurricanes (11%), since these events are less frequent.
The frequency of extreme outdoor heat, poor air quality, and flooding impacting daily activities in the past year increased the chances for believing climate change is increasing the risk of heat-related illnesses, respiratory diseases, and insect-borne diseases in the U.S.
Heat and severe weather are hitting household budgets
Nearly half of Americans (46%) say that during the past year they have had unexpected utility expenses caused by storms, flooding, heat, or wildfires, statistically unchanged from 45% in August 2025.
Thirteen percent report unexpected homeowner's insurance premium expenses from these causes, down significantly from 18% in August 2025, while 8% report unexpected health care expenses, unchanged from a year earlier.
Extreme heat affecting bills, activities, sleep, exercise – and pets
Respondents were asked the extent of the impact, if any, that extreme heat has had on their activities and lifestyle over the past year. Given the choices of "major impact," "minor impact," "no impact," "not applicable," or "not sure," majorities say it has had either a major or minor impact on their electricity bills (82%), outdoor activities (75%), exercise routines (56%), and sleep (56%). Some of these effects have increased since August 2025. The proportion reporting a major or minor impact on exercise and sleep increased to 56% from 50%, while the impact on pets increased to 45% from 37%, all statistically significant increases.
Most Americans still don't know where to find a cooling center
Despite the widespread effects of extreme heat, 65% of Americans say they do not know the location of a cooling center they could go to in the event of extreme heat. Just 35% say they know where one is located.
Knowledge has shown little recent improvement: 35% knew the location of a cooling center in August 2025 and 33% in July 2024. But knowledge is significantly higher than in November 2023, when 30% knew where to find one.
"As we continue to experience extreme heat," said Laura A. Gibson , an APPC research analyst, "communities need to do more to make the public, particularly vulnerable populations, aware of these cooling facilities."
Majority say their area has experienced unhealthy air quality
Unhealthy air quality is related to extreme heat. During the summer of 2026, much of the nation experienced smoky and hazy air quality from wildfires. Six in 10 Americans (60%) say the area where they live experienced days in the past three months when local health authorities reported that the air quality was unhealthy, up significantly from 48% in August 2025. Another 24% say their area did not experience such days, while 16% are unsure.
Those who say their area experienced unhealthy air quality took various steps:
- Stay indoors: 82% say they responded to local authorities' air-quality warnings by staying indoors more than they typically would, an increase from 76% in August 2025 and 74% in August 2023.
- Close windows: 51% closed their windows, compared with 45% in August 2025 and 48% in August 2023.
- Use a/c: 48% turned on the air conditioning, statistically unchanged from 47% in August 2025 but significantly higher than 37% in August 2023.
- Use an air purifier: 22% turned on a room-air purifier, compared with 19% in August 2025 and 17% in August 2023.
- Wear a mask: 12% wore a KN95 or N95 mask outdoors, up significantly from 7% in August 2025 and statistically similar to 9% in August 2023.
Six in 10 expect greater risk of heat stroke
A majority of Americans expect the dangers associated with extreme heat to grow. Nearly 6 in 10 (59%) say people in their community will be more likely to experience heat stroke caused by extreme heat waves in the next 10 years. Twenty-nine percent say people will be about as likely to experience it, 4% say they are less likely, and 8% are unsure.
The percentage expecting a greater risk of heat stroke is essentially unchanged from August 2025 (59%) and July 2024 (58%) but remains significantly higher than the 52% recorded in November 2023.
Knowledge of heat-related illness symptoms remains uneven
Most Americans correctly recognize several signs of heat-related illness, although knowledge varies considerably by symptom.
In August 2026:
- 88% identify dizziness as a sign of heat-related illness.
- 83% identify nausea.
- 72% identify hot, red, dry, or damp skin.
- Just 47% identify cold, pale, and clammy skin.
Only 5% incorrectly identify hunger as a symptom.
"Most Americans recognize that climate change is increasing the risk of heat-related and other illnesses, but our findings show that recognizing the risk doesn't always translate into knowing the signs of heat-related illness," said Winneg. "That knowledge can be especially important as extreme heat becomes an increasingly common part of Americans' lives."
Knowledge of risks to pregnant people remains low
Americans remain much less knowledgeable about the risks extreme heat poses during pregnancy. Only 32% know that pregnant people exposed to extreme heat are more likely to deliver their babies early than pregnant people who are not exposed to extreme heat.
Nearly half (49%) say they are not sure, 17% incorrectly say pregnant people exposed to extreme heat are just as likely to deliver early, and 3% say they are less likely to do so. Knowledge has not significantly changed from August 2025 (33%) or July 2024 (30%), although it remains significantly higher than the 24% who knew this in November 2023.
Older adults correctly identified as most vulnerable to heat-related deaths
More than two-thirds of Americans (69%) correctly identify adults ages 65 and older as the age group in which heat-related deaths are most common. Eight percent say children, 2% say adults ages 21 to 40, and 4% say adults ages 41 to 64. Sixteen percent are unsure.
Knowledge is unchanged from August 2025, when 69% identified those 65 and older, but is significantly higher than in August 2022, when 62% did so.
About the survey
The survey data come from the 30th wave of a nationally representative panel of 1,904 U.S. adults conducted for the Annenberg Public Policy Center by SSRS, an independent research company. Interviews were conducted by web and telephone Aug. 4-17, 2026. The margin of sampling error for the full sample is ±3.2 percentage points at the 95% confidence level. Data were weighted to represent the U.S. adult population.
Download the topline and the methodology statement .
The Annenberg Public Policy Center has been tracking the American public's knowledge, beliefs, and behaviors regarding vaccination, Covid-19, flu, RSV, climate and other consequential health issues through its Annenberg Science and Public Health survey panel.
In addition to Gibson and Winneg, APPC's ASAPH survey team includes Patrick E. Jamieson, director of the Annenberg Health and Risk Communication Institute, which oversees the ASAPH survey; research analyst Shawn Patterson Jr.; and Kathleen Hall Jamieson, APPC's director emerita.
See other recent Annenberg health survey news releases:
- Mosquitoes and disease: Most Americans know how to control mosquitoes; many unsure how to use insect repellent. (Sept. 10, 2026)
- Confidence in public health officials: Public confidence in Fauci declines since spring, but still exceeds RFK Jr. (Sept. 9, 2026)
- Confidence in healthcare providers: Public confidence in one's own healthcare provider remains high (Aug. 31, 2026)
- Banning glyphosate: Bipartisan majorities in U.S. favor banning glyphosate (Aug. 20, 2026)
- Recommended vaccines during pregnancy: Most Americans are unsure which vaccines the CDC recommends during pregnancy (July 22, 2026)
The Annenberg Public Policy Center was established in 1993 to educate the public and policy makers about communication's role in advancing public understanding of political, science, and health issues at the local, state, and federal levels.
