Deciding when to visit Utah depends on what you want to do and which places you want to see. Those traveling without children will likely want to avoid visiting during school vacations. In particular, stay away from ski resorts during the Christmas-New Year's holidays and avoid national parks in July and August. The best time to visit the parks and almost everything else in southern Utah is spring or fall; summer is too hot, particularly in St. George.
Utah has four seasons, but because of the wide range of elevation -- from 2,200 to 13,528 feet -- conditions vary considerably across the state. Generally, as in other desert states, summer days are hot but nights are cool. Winters are cold and snowy, except in southwest Utah's "Dixie" (which includes St. George), where it seldom gets very cold and snow is rare. Mountain temperatures are always pleasantly cool and can be quite cold at night, even in summer.
