How many constellations are there in the sky?
Their are 88 constellations in the sky.
In astronomy, however, a constellation is an area of the sky, and contains all the stars and other celestial objects within that area. The International Astronomical Union (IAU) divides the sky into 88 official constellations with exact boundaries, so that every direction or place in the sky belongs within one constellation. Most of these constellations are centred on the traditional constellations of Western culture.
Due to the rotation of the Earth, the constellations overhead in the day time (which are not visible as it is) are not the same ones visible at night. However, the constellations in today's day sky are the same constellations in the night sky 6 months from now, and the constellations in tonight's night sky are the same constellations in the day sky 6 months from now.