Averagemonthly rainfall in Kerala
Month Rainfall(mm)
January 14.6
February 16.6
March 36.1
April 110.9
May 252.6
June 653.2
July 687.2
August 404.7
September 252.3
October 270.7
November 158.6
Cannanore Kannur
December 45.9

Kerala Rainfall Trends

Attempts were made to study temporal variation in monthly, seasonal and annual rainfall over Kerala, India, during the period from 1871 to 2005. Longterm changes in rainfall determined by Man-Kendall rank statistics and linear trend. The analysis revealed significant decrease in southwest monsoon rainfall while increase in post-monsoon season over the State of Kerala which is popularly known as the “Gateway of summer monsoon”. Rainfall during winter and summer seasons showed insignificant increasing trend. Rainfall during June and July showed significant decreasing trend while increasing trend in January, February and April. Hydel power generation and water availability during summer months are the concern in the State due to rainfall decline in June and July, which are the rainiest months. At the same time, majority of plantation crops are likely to benefit due to increase in rainfall during the post-monsoon season if they are stable and prolonged.

Kerala Rainfall Trends - Red Rain

From July 25 to September 23, 2001, red rain sporadically fell on the southern Indian state of Kerala. Heavy downpours occurred in which the rain was coloured red, staining clothes with an appearance similar to that of blood. Yellow, green, and black rain was also reported. Coloured rain had been reported in Kerala in as early as 1896 and several times since then.It was initially announced that the rains were coloured by fallout from a hypothetical meteor burst, but a study commissioned by the Government of India found that the rains had been coloured by airborne spores from a locally prolific terrestrial alga. Other explanations were proposed but not until early 2006 did the coloured rains of Kerala gain widespread attention in the popular media. A controversial conjecture that the coloured particles were extraterrestrial cells was proposed by Godfrey Louis and Santhosh Kumar of the Mahatma Gandhi University in Kottayam.No information to support the extraterrestrial hypothesis has been published since 2006.