Rainfall is the primary means by which the earth is supplied with water. In a country like India, food production and economy depend on the timely accessibility of water, study of rainfall trends are critically important. In the present study, statistical analysis is being conducted to determine the potential trend in seasonal and annual rainfall time series in the Bhadar river basin in Saurashtra, Gujarat, between the years 2000 and 2020. A detailed statistical analysis is executed using commonly applied methods like Mann–Kendall’s test and Sen’s slope. Study reveals very high seasonal rainfall variability in an entire study area. The data confirmed that rainfall is predominantly concentrated in the monsoon season. Significant increases in trend can be seen in post-monsoon season which indicate shifting of rainfall pattern toward post-monsoon season. This study suggests the importance of a regional approach to water resource management for the Bhadar river basin.