Concerning trends don’t necessarily lie in record temperatures.
Wilmington sees an average of seven more days a year over 90 degrees than it did 50 years ago. The state is tied with Arizona as the fourth-fastest warming state based on temperature trends since 1970.
Average temperatures are projected to increase 2.5 to 4.5 degrees by 2050, from 2012 averages. That could rise up to 8 degrees by 2100, according to Delaware’s Department of Natural Resources and Environmental Control, in the worst emissions scenario. This stands to impact health, infrastructure, agriculture and more.
This summer, Delaware can expect higher temperatures than its used to, according to National Oceanic and Atmospheric Administration projections, while Wilmington in particular has a 55% likelihood of a heat wave lasting three days or longer this year, per First Street research.
But all of this could still make you curious: What have the hottest days recorded across Delaware looked like?
Who knows what’s to come.
[Note: Do you struggle with heat? Delaware Online/The News Journal is placing special emphasis on heat impact this summer, as part of an ongoing Perilous Course project across USA TODAY Network Northeast. Reach out: kepowers@gannett.com.]
110 degrees — July 21, 1930
One station in Millsboro recorded a scorcher back in the 20th century, according to the National Weather Service.
The reading came in at 110 degrees Fahrenheit, on a summer day in late July. That temperature in one Sussex County town reflects the highest max temperature in available data in the First State.
Note these temperature records do not account for humidity.
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Every 1 degree Celsius temperatures climb, according to First Street research, the air holds about 7% more water vapor. This means humid days in general are increasing, alongside a higher likelihood of hazardous heat. Measuring heat index, or how hot a day “feels,” combines both temperature and humidity.
Hazards arise as more humidity makes it harder for the body to cool off by sweating. It’s especially dangerous for your kids, pregnant people and older adults — while those with respiratory illnesses, diabetes and obesity maintain the highest risk.
Moving on.
107 degrees — Aug. 7, 1918
This maximum was recorded at Wilmington City Hall a dozen years earlier. That early August day in 1918 reached 107 degrees, according to the National Weather Service.
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Today, some areas of Wilmington likely experience more heat than other corners of Delaware. Dense urban areas feel heat exacerbated, as concentrations of dark materials like asphalt, steel and brick trap heat between buildings and streets — also called the “urban heat island effect.” The same surfaces will release heat slowly over the course of the night, making the cooler evening hours hotter than they should be.
Typically, Wilmington forecasts from the National Weather Service come with readings taken at New Castle Airport. That’s some 5 miles from the city center.
105 degrees — July 10, 1936, and July 16, 1983
Here we have a tie. Actually, a three-way tie.
On a sweltering July day in 1936, both Milford and Bridgeville posted one of the highest temperatures in Delaware history, according to the National Weather Service. The Kent and Sussex locales reached 105 degrees.
Nearly 50 years later, that temperature would be reached yet again in Newark. Another mid-July day showed 105 degrees in the New Castle County city. In data provided to Delaware Online/The News Journal, meteorologists noted this temperature occurred one or more additional instances as well.
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104 degrees — July 11, 1936; June 9, 1984; and July 23, 2011
Delaware has clearly had some hot July weather.
Again stations in Delaware City, Georgetown and Middletown posted their highest temperatures with a shared record. That maximum came in at 104 degrees. For Delaware City’s Reedy Point, that was in July 1936, while June 1984 came with max temperature in Middletown. The airport in Georgetown saw its max in July 2011.
In data provided to Delaware Online/The News Journal, meteorologists noted this temperature occurred one or more additional instances as well.
Have a story? Delaware Online/The News Journal is placing a special emphasis on heat impact this summer, as part of an ongoing Perilous Course project across USA TODAY Network Northeast. Contact this reporter at kepowers@gannett.com or (231) 622-2191, and follow her on Twitter @kpowers01.
