Prova's sky resembles our own: fluffy clouds, blue skies, one sun during the day and one moon at night. It is the sun and the moon that are the most important, as these are the primary figures of the major Provan religions.
Prova has one moon, which is considered holy by those who follow the Lunan religion. It is believed that Luno resides on or within this moon, and listens to prayers from there. Although Luno is closely associated with the moon, she is not explcitly a "moon god" - it is thought by most of her worshippers that she came from another place, outside of their own world, and lives in the moon to watch over their world for her own reasons.
The sun is a warm yellow star, and Prova exists directly in the "Goldilocks zone" for it. The sun is named Stelo, and it is considered the primary god for its worshippers. The sun, interestingly, is not anthropomorphized. It is called an "it" by its worshippers, and there is no distinct "sun god". The sun is seen as a sentient floating ball of fire in the sky with a will of its own.
The sky is blue, but magical particles in the air have caused strange refractions of light in especially magically-charged areas. Green, yellow, and purple skies are typical where large amounts of magic "radiation" are present. These skies are considered bad omens by the people of Prova, and are unpleasant reminders of the Magic Crisis.