If you're looking for a Nokia Lumia model that is resistant to water and dust, you could check out the Nokia Lumia 620 Protected Edition, offered by the Finnish based manufacturer; but unlike other handsets that are actually certified as water and dust resistant, like the Samsung Galaxy S4 Active and the Sony Xperia Z, the Nokia Lumia 620 relies on a rugged case with IP 54 certification to protect it from the elements...
Source: http://www.phonearena.com/news/Nokia-Lumia-620-bundled-with-IP-certified-case-to-become-the-Protected-Edition_id46748
Source: http://www.phonearena.com/news/Nokia-Lumia-620-bundled-with-IP-certified-case-to-become-the-Protected-Edition_id46748