Thandai, sardai or thanday () is an Indian cold drink prepared with a mixture of almonds, fennel seeds, watermelon kernels, rose petals, pepper, poppy seeds, cardamom, saffron, milk and sugar. It is native to Indian Subcontinent. It is mainly used in summer. In Northern Indian Hindu culture, it is often associated with the Holi or Holla mahalla festival. It is most commonly consumed in hot areas of North India and Punjab. There are variants of thandai and the most common are badam (almonds) thandai and bhang (cannabis) thandai.
Thandai is a centerpiece of Holi celebrations where other snacks like dahi vada, gujiya and other savory snacks called chaat are served alongside the cold, sweet beverage.
Though thandai refers to a traditional festival drink made with various spices and nuts, this versatile drink can also be prepared in many different ways.