The ground-level clouds of tiny water droplets known as fog are all at once beautiful, mysterious, hazardous, and beneficial. The foggiest place on Earth is the area called the Grand Banks off the coast of Newfoundland. The Grand Banks experience more than 200 days of fog a year. Fog can make driving, flying, and other forms of transportation more difficult due to reduced visibility, and in frozen form, fog can damage trees, power lines, and freeze on roadways to make them slick and dangerous. But fog has its benefits, too, providing moisture to plants and crops in coastal and other areas. In some regions of the world, fog is even being harvested in specially designed water traps for domestic and agricultural use.

But weather patterns and climates are shifting causing when and where fog occurs to change as well. Places, such as the farms and orchards of California’s Central Valley, no longer experience as much fog as they used to see. NASA’s instrument data can provide current and historical data to map where fog develops and under what conditions to help researchers and planners predict where it likely will—or won’t—form in the future.