The existing health situation of jackfruit seedling of nursery diseases of jackfruit species in Bangladesh is in a stage to be upgraded for successful fruit production to meet the national demand. Experiments were carried out during the period of July, 2012-October, 2014 to study the incidence and severity of leaf blight of jackfruit seedling in some selected area of Bangladesh on the Effect of weather components. From the experiment the highest incidence (44.17%) was recorded in April (2013 & 2014) when the average temperature, relative humidity and rainfall were 21°C, 70.72% and 3.68 cm, respectively. On the other hand, lowest incidence (3.21%) was recorded in January (2013 & 2014) having average temperature, relative humidity and rainfall 17.67°C, 74.90% and 0.56 cm, respectively. In case of disease severity of jackfruit seedling the highest severity (38.59%) was recorded in April (2013 & 2014) when the average temperature, relative humidity and rainfall were 21°C, 70.72% and 3.68 cm, respectively. On the other hand, lowest severity (1.27%) were recorded in January (2013 & 2014) having average temperature, relative humidity and rainfall 17.67°C, 74.90% and 0.56 cm, respectively.