Rain

Due to the direct effect of south-west monsoon that supports tropical evergreen forest belt. The shifting of Inter Tropical Convergence Zone (ITCZ) over the continent and its (Meghalaya plateau) transverse location between the Eastern Himalayas on its north and the Bay of Bengal in the south leads to a direct contact of moisture laden winds with the plateau. Location of Cherrapunji on southern edge of the Meghalayan horst causes high rainfall to oc-cur, while orographic effects control the processes of water circulation of this area (O'Hare 1997; Starkel, Basu 2000 p. 4). Monsoon circulation is checked by the southern foreland of the Meghalayan horst because of its steep slopes, vertical effects of rising moist air masses and conditions of condensation at about 1,000 m a.s.l.

A second specific feature of Cherrapunji area pertains to its geological structure, which controls the water circulation and evolution of relief. The horizontally bedded sandstones and limestones in the region overlie the metamorphic and igneous rocks, raised to an elevation of 1,200 to 1,900 m a.s.l. along the tectonic fault. They are dissected by deep gorges separating several spurs of the plateau. Cherrapunji is located at one of such spurs. Lithology of the area is reflected in a step-like morphology of slopes and river channels on the spur, which differentiate the prevailing sandstone part, and most of the southern limestone belt characterised by karst topography. (Starkel and Singh,2004)

Scientific recording of rainfall at Cherrapunjee was initiated after the Khasi Hills was annexed to the British Empire. After India attained Independence the India Meteorological Department continued the rainfall recording.

Current annual average rainfall is 12,500 mm with an exceptional high of 24,650 mm recorded in 1974 (Indian Meteorological Department).

It holds two Guinness world records for heaviest rainfall .A month long record of 9,300 mm (366 in) in July 1861 and a 12-month record with 26,461 mm (1,041.75 in) between 1 August 1860 and 31 July 1861.

A World Meteorological Organization (WMO) panel announced that "Cherrapunji now holds the world record for two-day (48-hour) rainfall, with 2493 millimeters (98.15 inches) recorded on June 15-16, 1995".(TOI,April 2014)

Rainfall Data

YearRainfall in mmYearRainfall in mmYearRainfall in mmYearRainfall in mmYearRainfall in mmYearRainfall in mm
1851NA188110556.494191114230.9194111322.51971846920018971.5
185211514.58218828107.6819129851.819429643.11972NA200212262
185313322.318839438.64191310641.7194310372.7197310910.1200310498.8
185414035.53218848086.85219149199.619449469.4197424555.3200414790.8
1855NA188511238.484191512874.819459891.4197511961.420059758
1856NA188611752.072191612350.81946NA19769019.420068734.1
1857NA188711188.19219179848.3194711293.1197712109.7200712646.8
1858NA188810623.296191812708.819481421119786950.3200811414.6
1859NA188913460.22219199472.9194912494.9197912094.820099069.9
1860NA189013749.27419209391.11950956019809132.9201013472.4
1861NA18917690.104192113209.3195115846.219819417.520118732.2
1862NA189214036.802192210651.7195211073.8198210380.8201213364.2
1863NA189312213.84419239643.8195312416.41983976420137560.3
186412398.24818949708.134192411880.2195413521.3198416760.7  
186512804.1418959263.3819259116.6195513608.3198511816.3  
1866NA18967819.13619261018619561378319868139.5  
1867NA189711870.182192711095.319579559.8198713153.3  
1868NA189812227.56192810019.4195810564198817930.4  
1869NA189916304.514192911073.6195911595.3198913460  
1870NA190011312.90619309181.11960NA199011597.7  
1871NA19019467.342193112043.81961NA199113505.9  
187212136.882190211793.728193212360.71962680719928356.5  
18737188.2190310334.75219338105.51963NA199312801.3  
187410732.7719049436.608193413826.11964NA199411204.8  
187510377.932190512605.258193511801.81965NA199514209.8  
187611921.49190612377.4193610319.2196611389.9199612896.6  
18779712.9619079180.9193787451967794719978993.6  
187814019.27619087178.2193813945.1196810749.7199814536.9  
187912372.84819098286.3193910650.519698921.7199912502.8  
188012911.328191012360.619409635.7197017200.1200012262.2 

Source: From 1851- 1905: ‘World Weather Records’, Smithsonian Miscellaneous Collections Vol. 79, p. 246 published by the Smithsonian Institute in 1929. From 1906-2013: India Meteorological Observatory at Cherrapunjee by cherrapunjee resort