Question

Why the sun does not appear in the noon hours

Answer 1

During noon hours,the distance to be travelled by the sun rays in the atmosphere is less than that compared to morning and evening hours. therefore all colours reach our eye without much scattering. hence the sun appears white during noon hours. 

Answer 2

During noon, the distance that sunlight has to travel to reach us is less than during morning or evening. Thus the scattering is very less and all lights enter our eye. So it appears white as combination of all colours of light give white light.