The Ardh Kumbh Mela is celebrated every six years at Haridwar (a pilgrimage city in the Haridwar District of Uttarakhan in India) or Prayag (a city in the North Indian state of Uttar Pradesh).
Purna Kumbh Mela (great Kumbh Mela) occurs every 12 years, but the Ardh (half) Kumbh Mela is also observed every 6 years.
The next Ardh Kumbha Mela will be from August 15 to September 13, 2015.