Rainfall and temperature trends were investigated at four stations representing three agroecological zones of Bihar using 45 years data except for Sabour (34 years) and Madhepura (43 years). Monthly, seasonal and annual precipitations as well as temperature (Tmax and Tmin) were analyzed for climate variability and possible trends using nonparametric Mann-Kendal statistic test. The results showed an increasing trend in rainfall and minimum temperature, on the contrary a decreasing trend for maximum temperature in the study area.