This research article published by the Journal of Mathematics and Informatics, Vol. 15, 31 January 2019Northern Corn Leaf Blight (NCLB) disease is a fungal foliar disease caused by Exserohilum turcicum. Moderate temperature and high relative humidity are climatical conditions which favor the development of NCLB disease. A deterministic model for transmission dynamics of NCLB disease with seasonal weather variations is developed and vigorously analyzed. The basic reproduction number in the absence and presence of the impact of temperature and relative humidity is computed and the sensitivity analysis performed to determine the parameters’ relationship with basic reproduction number . The analysis shows that transmission rate from pathogen to susceptible maize plants, the pathogen’s shedding rate from infected maize plants to the environment and maize plants disease induced death rate are more sensitive to NCLB disease dynamics and they play an important role in its transmission. On the other hands when there are high or low temperature and low humidity, sensitive negative parameters increases as the results NCLB disease development decreases. However, increasing parameters such as natural death rate of the pathogen, the natural death rate for maize plants and maize plants’ disease induced death rate which have negative indices will reduce new infections. Moderate temperature and high relative humidity influence NCLB disease development.