Аннотация:The results of the analysis of data on monitoring the level and temperature of water in January 2015 – July 2019 and air temperature in January 2015 – February 2016 in the “old” (Penelope Hall) and “new” (Morozov Lake) parts of the bottom gallery of the Snezhnaya cave system are presented. The average water temperature in the Penelope Hall is +5,92±0,13°C and it lies in the range from +5,32°C to +6,16°C; the average water temperature near the Morozov Lake is +6,08±0,21˚C with maximal and minimal values of +5,56˚C and +6,60˚C. The air temperature in the Penelope Hall ranges from +5,77 to +6,16˚C with an average value of +6,00±0,10˚C. The air temperature on Morozov Lake does not change throughout the year, it ranging from +6,41 to +6,53˚C with an average value of +6,47±0,02˚C. The maximum height of the water level rise in the Penelope Hall reaches 58-59 m for single floods and 58-60,5 m for long-term floods. In the case of Morozov Lake, the height of water rise in the case of extended floods is 10–15 m higher than for single floods: 61-66 m versus 50–53 m. The maximal levels of water are 71,5 m in Penelope Hall and 81,4 m in Morozov Lake. In the Penelope Hall, the characteristic alues of the maximum rate of water rise are 30-38,5 m/h in the case of single floods and 17-30 m/h for extended floods. Near the Morozov Lake, еhe maximum values are 13,6-14,7 and 9-10,5 m/h, respectively. Water reservoirs in the old and new parts of the Snezhnaya cave system do not communicate with each other. There is no hydrological connection through possible gaps at lower altitudes relative to the Metrostroy Hall between the Throne Hall and the Penelope and X Halls. The results indicate the existence of two separate hydrological and climatic systems with significant differences in the morphology the old and new parts of the cave system.