Hotter summer nights are raising health risks in Oregon
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Looks colder than it is. Photo: Wolfgang Kaehler/LightRocket via Getty Images
Broiling high temps like we've had the last few days get the headlines, but when the day is done, overnight summer temperatures are actually rising faster than daytime highs in Oregon.
Why it matters: Hotter nights leave people with less time to recover from daytime heat, experts say, increasing health risks as Oregon's climate continues to warm.
The latest: The low overnight Thursday in Portland was 66° F, 7° higher than usual, according to the National Weather Service.
By the numbers: The average low temperature for summer nights has gone up by 3.7° F between 1970 and 2024, per Climate Central, a climate research group.
- Rising nighttime temperatures have resulted in the loss of 24 hours of sleep for every Portlander annually, the group reported in a new study, with 15% of that sleep loss directly attributed to climate change.
- Between 1951 and 2020, Portland averaged just under two days per year that saw minimum temps of 65° F or higher, according to a climate assessment from the Oregon Climate Change Research Institute.
- In 2021 and 2022, there were 17.
Threat level: Heat can have a cumulative effect on the body and warming overnight temperatures can have serious health implications, OCCRI director Erica Fleishman told Axios.
- "Extreme night heat has been associated in many cases with additional mortality, with additional hospital admissions, with more cardiovascular problems."
- Fleishman noted that older folks, people with health conditions and people experiencing homelessness are particularly vulnerable.
- If it's safe to do so, opening windows at night can provide some relief, but that's only true if the cool outside air isn't also full of wildfire smoke.
The bottom line: As the Rose City's long, hot summer continues, hotter nights mean Oregon residents may lose one of the body's most important opportunities to recover from that relentless daytime heat.