West LA Times

Signals from La Niña suggest a hot fall is ahead, with more prolonged heat waves similar to the recent one that set record highs across the West Coast.

The extreme temperatures were anticipated by climate scientists but may have surprised the general public, according to UCLA atmospheric scientist and statistician Karen McKinnon.

“This is what we were predicting, but now it’s what we’re feeling in everyday life,” McKinnon stated. “The recent heat dome isn’t unexpected under climate change, but it shows us how a few degrees make a big difference. We are all experiencing what summer extremes look like, even with what may seem like a modest level of warming. At the extremes, it doesn’t feel like a modest level of warming.”

McKinnon elaborated on the impacts of rising temperatures: “If your summertime temperatures are 4° F warmer than 50 years ago, your typical summer day might go from 84° F to 88° F, and you won’t really notice. But when your extreme summer temperatures go from 98° F to 102° F, the impacts start to pile up because our bodies are sensitive to those temperatures. On a mild summer day, no one notices climate change. The only times we notice are at the extremes.”

“We were living through a climate change extreme during the last heatwave. Across the board, the average daily high and low temperatures are higher. With climate change making everything warmer, by definition the heatwaves get longer,” she added.

Media are encouraged to quote from McKinnon’s comments or reach out for additional insights from her or other UCLA wildfire and climate experts.

Karen McKinnon is an associate professor studying climate extremes and large-scale climate variability at UCLA’s Department of Statistics and the UCLA Institute of the Environment and Sustainability.