The shout can be used to clear away fog and mist as well as snowy, cloudy, or rainy weather anywhere in Skyrim. It can also clear poisonous gas away from traps.
It can be used as an alternative to Unrelenting Force as it has a much quicker recharge, although it only works outdoors, and only causes enemies to stagger. It can be used to kill Salmon in order to harvest Salmon Roe or knock flying insects from the air in order to gather them as ingredients.
During Alduin's Bane, Clear Skies can be used to negate Alduin's "Dragon Storm Call".
The first word of the shout provides a longer period of clear weather per second of cooldown required when compared to using the second and third words. The first word provides five seconds of clear weather for each second of cooldown, versus the four seconds of clear weather for each second of cooldown for the second and third words.
The shout has no effect indoors.
The shout has no effect at the ash wastes of southern SolstheimDB.
The shout will clear away fog and rain at Dayspring Canyon, but not cloud coverDG.