The present study was carried out over Odisha, situated in the eastern part of India, to examine the monsoon rainfall trend for a period of 31 years (1988–2018). The rainfall data were observed at 314 blocks scattered all over Odisha. The time-series data of June, July, August and September were studied for their spatial and temporal variations. The analysis of rainfall trend will help to facilitate decisions regarding the cropping pattern, sowing date, and other purposes. To detect any significant trend in the monsoon rainfall and its magnitude, non-parametric test viz. Mann–Kendall and Theil-Sen’s slope was applied. Further, analysis was made of the trend with confidence interval at 95% level. As far as significant trend is concerned, the results indicate that, for the monsoon rainfall in June, there are increasing trends in 4 blocks and decreasing trends in 52 blocks, for July, there are increasing trend in 16 blocks and decreasing trends in 3 blocks, for August, there are increasing trends in 15 blocks and decreasing trend in 1 block and for September, there are increasing trends in 30 blocks and decreasing trend in 1 block. And for the total monsoon rainfall, there are significant increasing trends in 29 blocks and decreasing trends in 21 blocks. A significant decreasing trend in monsoon rainfall is observed during the months of June and August, whereas, a significant increasing trend is observed during the months of July and September. The present study is useful for planning and management of water resources to ensure sustainable availability and uses.