Why can high temperatures cause a greater potential for pesticide drift?

High temperatures significantly impact the physical characteristics of pesticide droplets during aerial application. When temperatures rise, the rate of evaporation of liquid is accelerated. This causes pesticide droplets to evaporate and become smaller much quicker than they would at lower temperatures. As these droplets shrink, they can be more easily carried away by wind, increasing the potential for drift away from the intended target area.

While increased wind speed and reduced humidity can also affect drift potential, the primary mechanism in this question is the evaporation of droplets at high temperatures. The increased surface area and aerodynamic properties of smaller droplets make them more susceptible to being moved by even light winds, raising the risk of drift towards non-target areas. The option regarding soil temperature does not directly relate to aerial application drift, making it less relevant to the question.