5 Safest Cities for Allergy Sufferers

Third-best city: Salt Lake City

Median list price: $198,900

"With its dry mountain climate, Salt Lake City has one of the best climates for freedom from respiratory issues," Sperling says.

Utah's capital has the lowest smoking levels of any city studied -- not surprising given the fact that the Mormon faith many residents practice bans tobacco use.

Salt Lake City also has the second-lowest flu incidence Sperling found, although residents do consume higher-than-average levels of respiratory medicines.

As for the local economy, Salt Lake City's major businesses include financial firm Zions Bancorp. and chemical manufacturer Huntsman (founded by the father of former GOP presidential hopeful Jon Huntsman). Other major local entities include privately held Sinclair Oil and the 23,000-student University of Utah.

Realtor.com has some 10,100 Salt Lake City-area properties listed for sale, from a $2,500 two-bedroom Park City, Utah, condo to a $49.5 million 60-acre estate that's also in Park City.