Cherrapunjee is a small town located on the southern edge of Khasi Hills, a dissected plateau at an altitude of about 4823 feet (1484 m) above mean sea level. The meteorological observatory is situated at 4267 feet (1313 m) above MSL. Cherrapunjee is locally and now officially known as 'SOHRA'. Khasi people of Mon-Khmer origin inhabit it. It is the headquarters of Sohra Civil Sub-Division and falls in East Khasi Hills District of the Indian State of Meghalaya. Meghalaya is one of the seven states of North East India with Assam to its North and sharing an international border with Bangladesh on its South.
As one proceeds northward from the Bay of Bengal over the plains of Bangladesh lying at almost sea level, the Khasi Hills erupt abruptly out of the flat lands towering to a height of about 4500 feet above MSL. Cherrapunjee falls directly on the path of Southwest Monsoon known as the Indian Summer Monsoon / Asian Summer Monsoon. The deep gorges around Cherrapunjee help to funnel and converge the low flying rain bearing clouds over Cherrapunjee. The upward thrusted rain clouds rapidly cool as they reach higher altitudes, condense and deluge Cherrapunjee. The process of cooling is assisted by the flow of air from north and north-east to the south in the upper atmosphere from the himalayan ranges. This is noticed about 10 p.m. or later at night. Again in the early mornings as the sun rays warm the hills the lightened air makes way for the clouds trapped in the valleys and hanging low over the Sylhet plains to move up. Most of Cherrapunjee rain is the consequence of air being lifted as a large body of water vapour. Major part of the rainfall recorded can be attributed to the orographic features of the Khasi Hills here. The heavy rainfall area indicated by Cherrapunjee is estimated to cover about 100 to 200 square km. Compare this to the heavy rainfall area of only 5 square km of Mount Weialeale in Hawaii (USA), which is in the middle of ocean. Cherrapunjee is about 400 km inland from the Bay of Bengal in the Indian Ocean and is home to over 25000 people.
The average annual rainfall at Cherrapunjee from 1973-2012 (40 years) is 11,859.4 mm (i.e. 38.90 feet- i.e. 466.90 inches). In 1974 it had rained 24,555.3 mm (ie 80.56 feet - ie 966.74 inches). The rainfall in 1974 at Cherrapunjee is the highest recorded annual rainfall in any one place in any one year in the whole World. On 16th June 1995, it had rained 1563 mm in 24 hours (ie 5.12 feet) - the highest recorded rainfall received in one place in one day.
98% of the annual rainfall at Cherrapunjee is received in just eight months from March to October. November, December, January and February get nominal or no rainfall. Rains during these months are mostly caused by cyclonic depressions in the Bay of Bengal. In Mount Weialeale it rains almost equally all the 12 months ? say about 1000 mm. At Cherrapunjee June gets an average of 2,481.9 mm and July 3,095.6 mm. It rained 8,204.7 mm in July 1974. July 2004 received 5014.6 mm of rainfall causing flood havoc in Bangladesh. The months of June and July put together account for 47.5% of the total annual rainfall at Cherrapunjee. Please see chart for average month-wise distribution of rainfall at Cherrapunjee and the annual rainfall at Cherrapunjee since 1951. For monthly rainfall data from 1901 please click on 'Rainfall Chart' in the Home Page.