Weather variability and climate change affect the application of pesticides in agriculture, in turn impacting the environment. Using panel data regression for the US, we find that weather and climate parameters significantly influence the application rates of most pesticides. Increased rainfall requires more plant protection for root crops and cereals and higher temperatures lead to increased pesticide applications to fruits and vegetables. The regression results are linked to downscaled climate scenario projections from the Canadian and Hadley Center climate models. We find that the application rates of most pesticides increase under both scenarios. However, the projected impacts vary considerably by crop, region, and pesticide.