National Iced Tea Day is observed in the United States every June 10, celebrating the popular beverage iced tea. The holiday honors iced tea's history, which dates back to the 1860s in the U.S. and gained significant popularity after the 1904 World’s Fair in St. Louis. Iced tea is made by brewing tea, chilling it, and serving it over ice, often sweetened or flavored with lemon, mint, or fruit. A distinct Southern variant known as sweet tea, made with sugar or syrup, became a staple of Southern cuisine. Iced tea accounts for about 85% of all tea consumed in the U.S., with classic lemon being the most popular flavor. Although the origin of National Iced Tea Day is unknown, it encourages people to prepare and share iced tea with friends and family, often shared on social media with the hashtag #NationalIcedTeaDay.