Variations of the sunspot period smoothed by a special filter have been found to be strongly correlated with long-term variations at the level of the Caspian Sea and the evaporation of the Aral Sea. The Caspian Sea's reply is delay on 10--16 years. The Aral Sea evaporation's replay interval is rather similar. It may be explained by the influence of the heat transportation by the Gulfstream flow in the Atlantic Ocean and changing the wind trend over the Caspian Sea. ¿ 2000 American Geophysical Union