The classification of the clarity with which objects can be viewed through the intervening atmosphere divided into 5 categories: Unusually Clear, Clear, Somewhat Hazy, Hazy, and Extremely Hazy. Sky visibility is an indication of the amount of aerosols close to the surface of the ground. The more aerosols there are, the more hazy it will appear. When observing sky visibility, look at a landmark in the distance and estimate how visible it is under the current sky conditions. Try to use the same landmark every time you observe visibility.
- This observation is only possible during the day, not at dusk or night.
- It can be helpful to take a picture of your sky day-to-day to notice the difference between visibility observations. In addition, the clearest sky for your area will be seen just after a front or a storm moves through your area.
These categories are intended as an approximate guide to the interpretation of the sky visibility choices.