Which weather conditions should you avoid when applying pesticides?

• A. Light breeze and overcast skies
• B. Moderate temperatures with no rain
• C. Clear, calm mornings
• D. Strong winds, rain, and extreme heat

Answer: (D)

Weather conditions shape how well a pesticide stays where you spray it and how safe it is for people, crops, and the environment. The goal is to apply when air is stable, rain isn’t likely right after, and temperatures aren’t extreme, so droplets don’t drift, wash off, or evaporate away too quickly. Strong winds push spray off-target, causing drift that can harm neighboring plants, wildlife, or people. Rain soon after application can wash the pesticide off the treated surfaces and increase runoff into water bodies. Extreme heat raises evaporation and volatilization, making drift worse and reducing how well the product sticks to plants, while also increasing exposure risk for workers. Because these adverse factors can happen together, you should avoid applying pesticides under conditions of strong winds, rain, and extreme heat. The other scenarios—light breeze with overcast skies, moderate temperatures with no rain, or a calm clear morning—tend to be safer and more effective.