Empirical study on erosivity of rainfall pattern in Singhanalli-Bogur watershed of the Northern transition zone of Karnataka, India was carried out to estimate the annual erosivity factor (Ra) and seasonal erosivity factor (Rs) and explain their correlation with the annual and seasonal rainfall as an indicator of potential erosion risks. Mean monthly erosivity factor was higher for July and lower for January while mean annual erosivity factor was higher for 2009 and lower for 2003. Highest monthly rainfall erosivity was obtained in July of 2009. On average, 2008 scored the highest summer rainfall erosivity factor while 2007 and 2010, respectively scored the highest monsoon and post-monsoon rainfall erosivity. The monthly-wise and season-wise analysis of the effect of rainfall erosivity revealed that July and monsoon season pose a moderate to strongly high erosivity risk in the area. The contribution of rainfall erosivity parameter to soil loss was low for 2001 and 2003, moderately high for 2002, 2004 and 2006, and strongly high for 2005, 2007, 2008, 2009, 2010 and 2011. Ameliorative measures through improved and integrated soil and water conservation technologies including selection of appropriate crops, no tillage, soil cultivation parallel with height contours, and terracing would be of immense help in reducing potential soil loss.