| 1961-1970 | 1971-1980 | 1981-1990 | 1991-2000 | 2001-2008 |
Mean water level (m) | 3195.81 | 3194.98 | 3193.91 | 3193.46 | 3193.63 |
Rate of water level changes (cm/a) | −8.10 | −14.30 | −0.30 | −9.50 | 5.30 |
Mean salinity (g/L) | 12.49 | 13.13 | 13.28 | 14.26 | 15.89 |
Mean precipitation (mm) | 377.04 | 365.13 | 402.11 | 370.93 | 390.43 |
Mean evaporation (mm) | 829.97 | 888.08 | 794.68 | 842.99 | 815.56 |
Mean temperature (˚C) | −0.81 | −0.48 | −0.39 | −0.07 | 0.46 |
Mean wind speed (m/s) | 3.68 | 3.81 | 3.59 | 3.42 | 3.19 |
Climatic types | cold-dry | cold-dry | cold-wet | warm-dry | warm-wet |