This book basically investigated the effects of weather factors (namely temperature, humidity, and wind speed) on Indian stock market. The study employed the secondary daily data of weather factors in five sample cities (namely Bangalore, Chennai, Mumbai, Delhi, and Kolkata) and two stock indices (called BSE Sensex and NSE Nifty) in India from January 1, 2001 through December 31, 2019. The analysis of GARCH Model showed that out of three weather factors in five sample cities, only one weather factors namely temperature in Bangalore City, Chennai City, Delhi City, and Kolkata City triggered the fluctuations in two sample indices while the OLS results clearly revealed that Temperature in Bangalore City, Chennai City, Delhi City, and Mumbai City did have significant impact on BSE Sensex and CNX Nifty; Humidity factor (in Bangalore City and Delhi City) had positive impact with BSE Sensex and CNX Nifty. The corporate policy makers, practitioners, fund managers, and National and International investors' may note this information while taking investment decisions.