Digital cameras made for your pocket should be made to handle any weather condition. I know that my Canon SD1000 is slightly sensitive to the weather, but I’ll tell you which camera can handle any conditions: the Nikon Coolpix eXtreme. The eXtreme can handle dust, snow, rain, etc.
I believe right now this camera is just a concept and isn’t available. It was designed by Camillo Vanacore.