Oregon Journalism Project: Air conditioning is becoming more vital to Oregon's public health and safety

For most of the past century, Oregon has reached 100 degrees about one day a year on average, says state climatologist and Oregon State University professor Larry O’Neill. But over the past five years, Oregonians have been subjected to five 100-degree days per summer.

As a result, far more people face heat stroke and other illnesses tied to overheating such as renal and heart failure, he says.

Those facing the highest risks are the elderly, people who live alone, and those with conditions such as heart disease, obesity, and other maladies.

“Historically, about 30% or 40% of dwellings had air conditioning and it only got used a couple of times a year,” O’Neill says. Climate change has upended that pattern.

Today, 82% of occupied Oregon housing units have some type of air conditioning, according to recent U.S. Census Bureau data. Significantly fewer homes along the Pacific coast have a cooling unit.

Sherman and Gilliam were the state’s two hottest counties from June to August last year. About 1 in 5 occupied housing units there lack air conditioning. In Malheur County, the state’s third hottest in 2025, only 1 in 20 lack cooling.

Air conditioning, especially in the Willamette Valley, has become a public health necessity rather than a consumer preference, says Vivek Shandas, a professor of earth, environment, and society at Portland State University.

“More people are being exposed to temperatures that their homes, infrastructure, and the public health systems were never designed to handle,” Shandas says.

The Oregon Legislature attempted to make cooling more accessible in 2022 with Senate Bill 1536, which ensured that all renters could install cooling units in their homes. In 2024, the state used Medicaid funds to provide air conditioning units to some residents.

Lawmakers debated sweeping change in the 2025 session with Senate Bill 54, which called for owners of buildings with 10 or more units to provide cooling solutions. The bill died in the Joint Ways and Means committee.

State and local governments have invested in programs to keep residents cool. The state has an incentive program that has given about 6,000 homeowners, landlords and new developments money to install heat pumps. The state’s largest city, which generates about $200 million annually from the Portland Clean Energy Fund for climate-related expenditures, has a specific program, Cooling Portland, that has supported delivery and installation of over 20,000 heat pumps in homes across the city.

While future policy changes could make cooling more accessible, O’Neill says people in the meantime should check on their neighbors and friends during heat waves, especially if they are at high risk. It could save lives.

•••

This story was produced by the Oregon Journalism Project (oregonjournalismproject.org), a nonprofit investigative newsroom for the state of Oregon.