Pink snow, blood snow or watermelon snow, looks like and even smells faintly of watermelon. The pink coloration is due to a cold-loving algae called Chlamydomonas nivalis. This phenomenon is common during the summer in alpine and coastal polar regions worldwide.
Watermelon snow, also called snow algae, red snow, or blood snow, is snow that is reddish or pink in color, with the slight scent of a fresh watermelon. It is caused by the presence mainly of Chlamydomonas nivalis, a species of green algae containing a secondary red carotenoid pigment (astaxanthin) in addition to chlorophyll. Unlike most species of fresh-water algae, it is cryophilic (cold-loving) and thrives in freezing water.Its specific epithet, nivalis, is from Latin and refers to snow.