Southwest monsson - youtube

Wettest seasons in chennai - records

Jan-Feb
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213mm = year 2000
60.2mm = year 2008
51mm = year 2004

Mar-May
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198mm = year 2004
166.6mm = year 2008
114mm = year 2005

Jun-sep
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677mm = year 2007
485mm = year 2001
442mm = year 2000

oct-dec
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2108mm = year 2005
1079mm = year 2001
985mm = year 2002

Overall
-----------
2566mm = year 2005
1668mm = year 2001
1402mm = year 2002

Rainfall stats for Chennai during Summer & SW monsoon-08

Mar-07 = 0mm (0%)
Mar-08 = 165mm (5500%)

Apr-07 = 0.4mm (1%)
Apr-08 = 0mm (0%)

May-07 = 0.2mm (0%)
May-08 = 1.6mm (3%)

Jun-07 = 94mm (174%)
Jun-08 = 125.2mm (232%)

Jul-07 = 249.2mm (254%)
Jul-08 = 29.4mm (30%)

As you can see the trend is like... Summer showers are getting lower, so hot and dry.
If showers occur that is heavy and squally.
These features are of desert.
Good thing is Chennai is getting more rain from South-west monsoon.