Spring and fall are the best times to visit Salt Lake City, as cooler afternoons give way to idyllic breezy evenings. Summertime high temperatures average more than 90° (June–August), with a few days above 100° each month. Winters bring snow, but abundant sunshine tends to melt it quickly in the valley. If your plans are taking you to Park City or the Cottonwood Canyons, follow weather forecasts closely, because a fluffy 6-inch snowfall in the city will often be accompanied by 3 to 5 feet "up the hill." Check weather forecasts closely if you have allergies. Extreme heat or cold without any wind often brings about "inversions" of polluted air that sometimes linger for longer than a week and prompt "red" alert warnings against activity in the valley. Escape to the mountains on these days. Most years, ski season kicks off by mid-November and ends in early April. (During a heavy snow year Snowbird Ski Resort will stay open on weekends as late as July 4.) Expect heavier crowds at the airport and higher rates at hotels and resorts that serve the ski slopes on wintry weekends, particularly around holidays such as Christmas, Martin Luther King Jr. Day, and Presidents’ Day. City accommodations are cheaper than those elsewhere in the country much of the rest of the year, but occasional large conventions significantly affect tourist travel to Salt Lake City. The largest is the Outdoor Retailers Show, which books nearly every hotel room in the city and surrounding suburbs during its weeklong winter and summer shows.
July 24 is celebrated statewide as Pioneer Day, and it’s a bigger deal than July 4 or any other holiday except Christmas. You may be able to catch one of the nation’s largest parades if you’re here on July 24, but also expect closed streets (because of the parade and a marathon), fireworks, and many closed businesses.