(As with Qinghai Lake, the Chinese word for "sea" is sometimes used to translate the Mongolian naɣur (ᠨᠠᠭᠤᠷ), which was once used ambiguously for all large bodies of water.)

[7] The mean annual temperature is −8 °C (18 °F),[5] so much of the surrounding countryside is permafrost[9] alpine grassland, supporting dwarf cinquefoil and winterfat shrubs and sparse sedges and grasses.

[9] During the Pleistocene, sediment from glaciers in the Kunlun temporarily blocked outflow of the valley's main meltwater stream,[7] forming the present lake.

[10] During the mid-Holocene, from around 8–4,000 years ago,[11] the climate was wetter and warmer, possibly from increased influence from the Indian[7] or East Asian monsoon.

Lake Heihai has a stone temple to the Queen Mother and a large slab reading "Xiwangmu Yaochi" (西王母瑤池).