Ozzi said:
would a lens filter of some sort help?
You could use a UV filter, sometimes called a Haze filter - this can help reduce haze, but also acts as a protective cover for the front lens element - fingerprints left on here can be cleaned off a lot easier than if they were on the lens itself.
Yoy may also want to consider a polarising filter, which will help give more contrast between clouds and sky (works best at 90 degrees to the direction of the sun) and can also be used as a Neutral Density filter if you want to cut down on the amount of light reaching the sensor. Make sure you get a Circular Polariser, not Linear, or you'll find that the autofocus won't work!