The present study investigates the impact of temperature, on the returns of the Carbon Index, otherwise called BSE GREENEX in India. The study employed the secondary data of temperature in five sample cities (Chennai, Delhi, Hyderabad, Kolkata, and Mumbai), and the BSE GREENEX in India. Statistical tools like Descriptive Statistics, Unit Root, OLS Regression Test, and Granger Causality Test, were used. This study would be useful for the investors to make green investment in India.