The Collaborative International Dictionary of English v.0.48:

Northward \North"ward\, Northwards \North"wards\, adv.
   Toward the north, or toward a point nearer to the north than
   to the east or west point.
   [1913 Webster]

WordNet (r) 3.0 (2006):

northwards
    adv 1: in a northern direction; "they earn more up north";
           "Let's go north!" [syn: north, northerly,
           northwards, northward]