Ashadha is the fourth month of the Hindu lunar calendar and the Indian national calendar. The name of the month is derived from the position of the Moon near the Purva Ashadha nakshatra (star) on the full moon day. The month corresponds to the beginning of the monsoon and falls in June–July of the Gregorian calendar.

In the Hindu solar calendar, it corresponds to the month of Mithuna and begins with the Sun's entry into Gemini. It corresponds to Asharh, the third month in the Bengali calendar. In the Tamil calendar, it corresponds to the third month of Aadi, falling in the Gregorian months of July–August. In the Vaishnav calendar, it corresponds to the fourth month of Vamana.

Rath Yatra that is dedicated to Jagannath is held in the month of Asadha every year in Puri and other places.

Guru Purnima, a festival dedicated to the Guru, is celebrated on the Purnima (Full Moon) day of the month. Prior to it Shayani Ekadashi, is observed on the eleventh lunar day (Ekadashi) of the bright fortnight (Shukla paksha). "Aadi Amavasai" is an important festival in Tamil Nadu and auspicious for Mariamman.

In many parts of Nepal, the arrival of monsoon marks a special time for cultivating rice. This occasion starts with farmers, men and women, planting rice (Nepali: राेपाइँ) while singing plantation songs. The farmers then participate in the mud festival, throwing mud at each other and welcoming the monsoon season. The festival ends with people sharing "dahi chiura (Nepali: दही चिउरा)" (literally "beaten rice with curds") with each other.

Kakkada month in Kodava calendar in Coorg, is considered one of the significant and auspicious days. Aati soppu, kakkada paayasa are the delicacies prepared on this day.

In many parts of Gujarat, Dashamaa Vart dedicated to Dashamaa or Momai maa is observed on the Amavasya of Asadha every year.

Significance, festivals and fasting of Ashadha month