Didn’t get enough sun during winter? These Northeastern and Midwestern travel destinations are solar-powered during spring.

Those who live in climates with cold and rainy winters know that being stuck indoors can have a negative effect on moods. Journalist Richard Louv coined the nonmedical term “nature-deficit disorder” to describe the “human costs of alienation from nature,” believing that this dearth can lead to behavioral changes in children who, because of the weather, are spending less time in the great outdoors. With spring’s arrival, it’s time to get back outside in the warm sun.

Cuyahoga Valley National Park...