Ten days and monthly mean temperatures were analysed daily data observed during July, 1916 to March, 1970 statistically. Periodic characters were calculated by Δn, new method of approximate solution of Schuster Method. According to ten days mean temperatures, annual variation function is F($ heta_d$)=16.29-5.27 cos $ heta_d$+0.75 cos2 $ heta_d$-3.14 sin $ heta_d$+1.16 sin2 $ heta_d$-0.63 sin $3{theta}_d$, where $ heta_d$=$-frac{pi}{18}$(d-3), d is the order of ten days period, 1 to 36. Annual mean water temperature is 16.3$^{circ}C$, minimum in the last ten days of February 10.9$^{circ}C$, maximum in the last ten days of August 24.5$^{circ}C$. Periodic character of secular variation shows 11 year and its curve is F($ heta_y$)=16.29+0.53 cos $ heta_y$ -0.16cos $2{ heta}_y$+0.10 cos$3{ heta}_y$-0.10 sin $ heta_y$, where $ heta_y$=2$-frac{2pi}{11}$(y-1920), y is calendar year. And the relation between air temperature x and water temprature y is following. y=9.67 1.035$^x$