Onam 2026 will be celebrated on Wednesday, August 26, with the grand Thiruvonam celebrations marking the most important day of the festival. The festivities traditionally begin with Atham on August 16 and continue through the ten-day celebrations leading up to Thiruvonam. Onam is one of Kerala's most important festivals and is known for its beautiful Pookalam, traditional Onasadya feast, Vallam Kali boat races, Thiruvathirakali, Pulikali, new clothes, cultural performances an