Climate Data Trends in Karnataka

            Average yearly mean temperature increased from 1970 to 1998 for all districts in Karnataka and all of the districts within Karnataka followed the same basic trend without cross-over, which is shown in the following figure.  The data showed that the hottest four months throughout Karnataka in order from hottest to coldest were April, May, March, and June.  These are the months that precede the onset of the monsoon, whose arrival causes a decrease in temperature.  The monsoon normally arrives in Karnataka in early June, which means that May and April are normally the warmest months, but with an early onset of the monsoon, March can become one of the hottest months.  And with a late onset of the monsoon, June’s temperature would not be modified by the monsoon and would be hotter than usual (Takahashi and Arakawa, 1981; Guha, 2000, personal communication).  The coldest three months in order from coldest to hottest were December, January, and November.

           Precipitation varied by district over the period of time of this study.  Three of the districts, Dakshina Kannara, Kodagu, and Uttara Kannara had much higher precipitation throughout the year than the other districts.  In Dakshina Kannara, Kodagu, Shimoga, and Uttara Kannara, which were some of the wetter districts, the wettest months were July, June and August.  In the remaining districts, June, July, August, September, and October were the wettest months in different orders depending on the district.  For all districts, January, February, March, and December were the driest months because they do not experience monsoons or cyclones.