While the sky is often blue due to the scattering of sunlight by the atmosphere, other factors can influence its color:

* Clouds: Thick clouds can obscure the blue sky, making it appear white or gray.

* Time of Day: At sunrise and sunset, the sky can appear red, orange, or pink due to the way sunlight is scattered through a longer path in the atmosphere.

* Pollution: Air pollution can cause the sky to appear hazy or even brown.

So, while the sky is most often blue on a summer day, there are many situations where it might not be.