Lake Taymyr is large, with a length of 165 km (103 mi) roughly east-to-west.

Its maximum width, however, is only about 23 km (14 mi) in its broadest area, towards the lake's eastern end.

The Lower Taymyra flows out of the lake northwards across the Byrranga mountain region.

Lake Taymyr is teeming with many kinds of fish typical of cold Arctic waters, such as loach, sig, and muksun.

This is perhaps a consequence of wind-carried particles after the numerous atmospheric nuclear tests in Novaya Zemlya during the Cold War.