How does humidity affect holdover times for de-icing fluids, and how should ground personnel adjust their procedures accordingly?

Humidity significantly affects holdover times for de-icing fluids because it influences the rate at which the fluid becomes diluted and loses its effectiveness. Holdover time is the estimated time a de-icing or anti-icing fluid will prevent the formation of ice and snow on an aircraft's critical surfaces. High humidity accelerates the dilution process. When humidity is high, the de-icing fluid absorbs moisture from the air more rapidly. This absorbed moisture dilutes the concentration of the fluid's active ingredients, such as glycol, reducing its ability to prevent ice formation. In conditions of ....