Aim: The maize is widely grown all parts of the world and it is consumed by all people. This paper studies the impact of climate variability on yield of maize crop in Tamil Nadu using Panel regression analysis. Study Design: Rainfall (max and min), Temperature (max and min) and yield details were collected from the Indian Meteorological Department and crop production reports respectively used for analysis. Place and Duration: Tamil Nadu, India. Methodology: Panel data model was used to estimate crop production functions. Results and Conclusion: The study focused on the impact of climate variability on yield of maize crop in Tamil Nadu using Panel regression analysis. The high rainfall leads to The effect of NEM rainfall on maize yield is dependent on the level of NEM temperature and vice-versa. This is probably because of the fact that in most of the districts in Tamil Nadu, maize is grown as a rainfed crop in north-east monsoon season with lower temperature and hence increase in temperature together with good amount of rainfall would lead to higher yield of maize.