The full moon day of Magha (January-February) is known as Maghi Purnima. It is a great bathing day and is of same significance as that of Kartik Purnima, for the practice of piety and devotion. On this day fast is observed and charities are done. Early in the morning, after ablutions, libations are offered to dead ancestors and the poor are given clothes, food, money, etc. Then Brahmins are fed and given dan-dakshina according to one's means and capacity.

As already stated, Magha is one of the four most sacred months. Therefore, a bath in Ganga on this day is of high religious merit. For those to whom Ganga is not easily accessible, they can bathe in any other holy stream, river, tank or pond. Moreover, Gangajal is kept in almost all the Hindu homes which may be poured into ordinary well water, and then used for bathing.

Bathing in India is a ritual, a ceremony, a festival and a great purifying act. A bath on such auspicious day as Purnima, is all the more significant. On this day great bathing festivals are held at various places along the banks of the holy rivers like Ganga, Yamuna, Sarayu, Narmada, Tapti, Kaveri, Krishna etc. People walk miles and miles to have a holy dip in the sea, or river or a lake on this day. A bath in the sea at Kanyakumari and Rameshwaram, is also considered to be highly rewarding. In the same way a dip at Pushkar Lake is also considered auspicious. At Kumbhakonam near Madras, there are great shrines of Sarangpani, Kumbeshwara and Nageshwara near which there is a large sacred tank, where devotees take a holy dip on this day. It is believed that Ganga flow into this tank on this day. Once every 12 years, Kumbha Mela is also held here.

Magha Mela is held at Prayag (Allahabad) on this day, and over a million devotees including pilgrims, ascetics, mendicants, nagas, priests, etc., take a holy dip here. People observe fast and charity on this occasion.