CHARLOTTE — When the sun goes down, we expect some relief from our summer heat, but these days, our overnight lows aren’t giving us much.
Take last month, for Charlotte, June 2025 was on the warmer side, but NOAA data shows, it was only our 12th warmest June on record in terms of average temperatures.
When it came to low temperatures though, it was the second warmest June on record, with temperatures on average 4.3 degrees warmer than the city’s typical overnight lows.
It’s a nationwide phenomenon. While dramatic high temperatures draw a lot of attention and post the most acute health threats, summer lows are trending warmer faster.
This means, when those dangerous heat waves come, nighttime isn’t providing much of a break.
“If it’s not cooling off at night, then it’s just kind of hot on top of hot, which makes it really uncomfortable for people, Dr. Raynard Washington, Mecklenburg County’s Public Health director, said.
If you have air conditioning, this probably means it’s running all night long driving up energy costs. If you don’t have air conditioning or can’t afford to run it full blast late into the night, the heat could be impacting your sleep.
Don Smith said he sets his AC to 76 degrees overnight to keep his bills reasonable, but on the hottest days, he notices all night long.
“I wake up sweaty all the time and shift positions and throw the cover off,” he said. “It’s rough, it’s hard.”
Washington said it’s even harder on those without shelter. While the risk of heat-related illness is at its worst during the hottest parts of the day, if exposure to high temperatures persist through the night, so do those health risks.
“Dehydration is likely one of the most common side effects of people having long exposure to heat,” he said. “Dehydration can lead to other health consequences, but also, individuals can have more severe like heat strokes and other kinds of more aggressive reactions”
Where you live can make a difference too. If you’re in the city, surrounded by concrete or asphalt, the urban heat island effect could raise the local temperature a few degrees, as that environment absorbs the heat during the day and takes much longer to cool down overnight.
Washington said the county’s cooling stations are meant to help but can’t stay open all day. He said shelters expand their capacity on the warmest nights like they would during a cold snap, and programs like this year’s free box fan giveaway targeted at-risk groups like seniors to try and provide widespread relief from the heat.
He also recommends neighbors check in on one another during these summer months, ensuring the most vulnerable have someone or somewhere to go if they’re feeling the impacts of the heat.
VIDEO: South Charlotte apartment residents endure 95-degree heat amid ongoing A/C failures
©2025 Cox Media Group
/cloudfront-us-east-1.images.arcpublishing.com/cmg/LH3JSJEF3VBLRJLJQESEAG34AM.png)
