Vassa is a Pali word, which means ‘rain’.  However, Vassa refers to the three-month annual retreat observed by Theravada Buddhists. Vassa is also known as the Buddhist Lent or Rains Retreat. It occurs during the wet season.

During Vassa, all monastics remain in one place. Some monks dedicated Vassa to intensive meditation. Some Buddhist devotees choose to observe Vassa by adopting more ascetic practices such as abstaining from meat, alcohol and cigarette.

Vassa is observed by Theravada Buddhists and Vajrayana Buddhists. However, most Mahayana Buddhists do not observe Vassa except for Vietnamese Thien and Korean Seon monastics.

Vassa begins on the day after Asalha Puja / Dhamma Day and ends on Pavarana, when each monk comes before the community of monks and make amends for his wrongdoing during Vassa.