Like many large rorquals, the fin whale is a cosmopolitan species. It is found in all the world's major oceans and in waters ranging from the polar to the tropical. It is absent only from waters close to the ice pack at both the north and south extremities and relatively small areas of water away from the large oceans, such as the Red Sea although they can reach into the Baltic Sea, a marginal sea of such conditions. The highest population density occurs in temperate and cool waters. It is less densely populated in the warmest, equatorial regions.