Many birds fly in foggy weather. Migratory waterfowl generally do not let fog stop them from continuing their journeys, although it may slow them down a bit. Local songbirds know their territories like you know your home. They can usually get from place to place within their “home” in the fog with little difficulty. If fog is quite a rare event (and has always been rare) in a particular region, you might find the fog reduces some bird activity, as they will have always lived in a region with good, clear visibility.

Remember, too, that most birds have vision capabilities that allow them to see further into the violet and ultraviolet spectrum, so the scattering of blue light that confuses human vision is not near the problem for most birds.