To understand the influence of weather parameters on the adult population of Hyblaea puera Cramer, correlation study was made on the number of adults trapped through the light trap. Total rainfall, minimum temperature and relative humidity (morning and evening) showed significant positive correlation with adult light trap catches where as maximum temperature had significant negative influence. Step down regression analysis suggested that total rainfall, minimum temperature, morning and evening relative humidity are the most important weather parameters which determine the population build-up in H. puera.