Abstract: The study is attempts to examine the impacts of weather changes on production of major crops like cotton, maize, rice, sugarcane and wheat of Pakistan. For this study, secondary data on cop production, precipitation and temperature were collected from various sources during 2005-2014, due to its availability. Results revealed that increase in one degree Celsius temperature, can bring change of 149.47 thousand tons in rice production, 3493.39 thousand tons in sugarcane production, which may declined 378.76 thousand tons in wheat production, 381.157 thousand tons in maize production and 55.27 thousand tons in cotton production. On the other hand, one additional millimeter rainfall can bring significant changes in all the cash crop productivity. While checking the reliability of the variables. It was found that Rsquare for rice, sugarcane, wheat, maize and cotton was about 0.6786, 0.6463, 0.6339, 0.6576 and 0.7143 respectively, which is considered as good fit to the model. This research suggests that technical information regarding the climate change should be disseminated to the farmers by Agriculture Extension and Research departments, since it has also impacts on the cropping calendar in the country.