Which condition increases drift? Low relative humidity and high temperatures.

Which condition increases drift? Low relative humidity and high temperatures.

• A. Low relative humidity and high temperatures
• B. High relative humidity and high temperatures
• C. Low relative humidity and low temperatures
• D. High relative humidity and low temperatures

Answer: (A)

Drift happens when spray droplets move away from the target due to evaporation and air currents. In dry air, water in the droplets evaporates quickly, and high temperatures boost evaporation even more. As droplets lose water, they become smaller and lighter, so they stay suspended longer and can be carried farther by the wind. This combination—low relative humidity plus high temperatures—produces finer droplets and greater drift than other conditions. Conversely, higher humidity or cooler temperatures slow evaporation, keep droplets larger, and reduce drift.

Drift happens when spray droplets move away from the target due to evaporation and air currents. In dry air, water in the droplets evaporates quickly, and high temperatures boost evaporation even more. As droplets lose water, they become smaller and lighter, so they stay suspended longer and can be carried farther by the wind. This combination—low relative humidity plus high temperatures—produces finer droplets and greater drift than other conditions. Conversely, higher humidity or cooler temperatures slow evaporation, keep droplets larger, and reduce drift.