Sizzling Day in North Dakota? Lately, It’s No Surprise.

After a morning filled with food and rides at a North Dakota county fair on Saturday, Bridget Bohn and her daughter, Clodagh, needed a break from the heat. They slumped on the ground in an air-conditioned building with water bottles by their sides, their cheeks flushed matching shades of red.

“We’re just trying to stay cool and healthy,” Mrs. Bohn, 36, said.

Clodagh, 5, chimed in from the floor, where she was lying on her back on the chilled concrete with a bag of cotton candy: “And not melt,” she said.

North Dakota is not known for scorching temperatures — the average high temperature in Fargo for July is in the low 80s. But on Saturday, Fargo and the areas surrounding the city were swept up in the same heat wave that gripped the West before shifting toward the Midwest and Northeast.

At the Red River Valley Fair, the heat index — a measure of how the weather feels when factoring in humidity — soared to 98, prompting the National Weather Service to issue a heat advisory for the afternoon. Forecasters warned that there was a major risk for heat-related illnesses because of the duration of the heat and how unusual it was for this time of year.

But at least on this day, and at this event, many North Dakotans shrugged off the high temperatures (flushed cheeks aside). The heat was something to take into account, perhaps by drinking water or taking breaks in the shade, but not cause for major concern.

“This is partly why we live in North Dakota,” said Louise Tegtmeier, 62. “Not too many 90-degree days.”