This question came from Kenneth who thought this observation, most often reported online, may not be useful much. He wasn’t far off from the truth. For the average person, 90% of the time, this statistic doesn’t mean much. It is reported to help pilots, of whom really depend on that information. There are a couple of exceptions. The visibility can also help us to determine where fog may be a hazard. It is also used to determine the intensity of snowfall.