Studies of the water temperature in the Shurinda thermal spring in the winter of 2009 and 2021 showed lower values in 2021. The number of habitats with different temperatures increased in the space of the thermal field. In 2021, 10 previously unrecorded species were identified in the flora of macroalgae and cyanobacterial mats, including aggregations of Spirogyra sp. The greatest diversity of cyanobacterial mats was found in the temperature range of 50-25°С; in the range of 20-10°С, accumulations of Spirogyra sp. occupied the entire water column. Cyanobacteria again prevailed in the area with a temperature of 4.0ºС. The higher species diversity of algae in March 2021 is due to the lower temperatures of the therms and their lower flow, which led to a greater diversity of temperature within the thermal spring.