Dealing With Frost
Frost most often develops just before sunrise and continues to build until the air starts to warm up. Frost delays our take off until the sun comes up and heats the top surface of the wings enough to melt it away. The "golden hour" of calm air in the morning is brief; it is frustrating to waste most of it scraping frost off the wings.

Clearing frost from the wing of the ultralight plane is a problem.
Photo: Operation Migration