Warm summer nights increase health risks in the morning and evening
Summer nights across Mid-Missouri are warming significantly due to climate change, increasing health risks through all hours of the day and night.
Heat is already the deadliest weather-related hazard in the U.S., and health officials recommend staying hydrated and indoors as much as possible.
Average summer low temperatures in Columbia have warmed by 3.1 degrees Fahrenheit since 1970, according to a Climate Central analysis of more than 231 U.S. locations.
Cities now experience an average of about 27 warmer-than-normal summer nights annually, a stark increase from the average of one such night per year in the 1970s. Sweltering nights limit the body's ability to cool off and recover from extreme daytime heat.
Shel Winkley, a meteorologist at Climate Central, noted that while much of the focus during summer is on extreme daytime heat, climate change is also increasing nighttime warmth. “In the United States since 1970, summer nights have warmed by an average of about three degrees,” Winkley said. “Today, these cities average nearly a month of hot nights each summer that were made at least twice as likely due to climate change. In the 1970s, that number was about one.”
Winkley emphasized the health implications of these warmer nights. “Sweltering nights limit our ability to cool off and recover from the daytime heat, raising the risk of heat stress and serious health impacts, especially when compounded with those very hot summer days,” he said.
This increased nighttime warmth is particularly dangerous because it prevents individuals from recovering physically from high daytime temperatures, compounding heat stress and related health risks. These risks are elevated for vulnerable populations, including people with chronic illness, young children, pregnant people, the elderly, and weather-exposed workers.
Health risks can also be higher in historically cooler climates, where people are less accustomed to these events and in urban heat islands. The risks further compound when extremely hot days and nights occur back-to-back.
Austin Krohn, Public Health Information Specialist for Columbia/Boone County Public Health and Human Services, stressed the importance of caution during warmer mornings and evenings. “Get out as early in the morning as you can or a little bit later into the evening, preferably,” Krohn said. He added, “Even in those evening hours, concrete and asphalt and things are absorbing heat all day and releasing that heat still. So please do take some caution still, because it's still going to be fairly warm out, even if you wait until the evening to do yard work or things like that.”
Krohn explained that sustained warm nights can be particularly detrimental to health. “When it's, I believe, sustained 75 degrees and above throughout the night, it's very hard for the body to catch a break from that heat,” Krohn said. “That kind of puts you in a bad position for the next day of sustained, extreme heat.”
To mitigate these risks, Krohn recommended consistent hydration. “A good recommendation is to stay hydrated even in the night when you're inside,” Krohn said. “Keep drinking water to make sure you're hydrated, even for the next day. So you can at least get some sort of jumpstart on that.”
He also highlighted other practical measures. “The AC is a huge one if you have access to that. Wearing lightweight, loose-fitting clothing, it should help quite a bit. Especially if you're struggling to cool off even indoors. Again, staying hydrated, that's the big one, especially when we have this sustained heat overnight.”
Krohn also specifically addressed the safety of outdoor workers. “I always think of our, you know, landscapers, construction workers really making sure they're taking frequent breaks, knowing their body, what their limits are, staying hydrated and making sure they're staying safe while they're on the job,” Krohn said. “Job won't get done if they're out sick.”
For those needing relief, several locations in the Columbia/Boone County area are available as cooling centers. These include The ARC, Columbia/Boone County Public Health and Human Services, City Hall, Salvation Army, and Salvation Army Harbor House.
