text: does the sky become a darker shade of blue as you get further from the equator? i only ask because i've lived basically along the same longitude line all of my life, and i've heard people from areas south of me comment on how much darker a shade of blue the sky is here.  if this isn't just an optical illusion or anything, please tell me so, and if you can, tell me why.  thanks. the sky in latitudes closer to the equator does appear to be a darker shade of blue, and here's why:  the blue color of the sky is caused by the scattering of wavelengths as the light from the sun penetrates the atmosphere. when the sun is overhead, short wavelengths (like blue and violet) get scattered the most, because the light has to penetrate less atmosphere to reach us. when the sun is low in the sky, as in during sunset, the light from the sun has to penetrate much more atmosphere than when it is overhead, because it comes in at an angle. as a result, the longer wavelength light (like red) penetrates more easily than the short-wavelength blue, which got scattered way back when the light first hits the atmosphere. this is why sunsets appear to be red.   with this in mind, consider that at latitudes near the equator are more likely, on average, to have the sun in a position more directly overhead than say, where i live, at about 45 degrees north latitude. hence, where i live, the short-wavelength light gets filtered out just a little bit more than where you live, creating a lighter-colored sky. i also live at high altitude (about 6500 ft.), which increases the effect. a little long, but hope this helps.