The tiny droplets of water that make up fog are so small that it would take seven thousand million of them to make a single tablespoonful of water.
The fogs, which are more common in winter, occasionally cause havoc with air travel by lingering into the early afternoon.
In Australia, Canberra wins the title of the 'foggiest' capital city with an average of 47 fogs each year.
Sea fogs persist for more than 120 days a year on the Grand Banks, Newfoundland, Canada