Drought assessment study is critical for the long-term development of both society and the environment in Algeria. Long-term monthly precipitation and temperature data (118 years) for Algeria were obtained from the Climate Research gridded time series (CRU TS v.4.05) database to calculate the SPI and RDI for short-term (3 months), mid-term (6 months), and long-term (12 months) series. As a result, the study of droughts in Algeria using long-term gridded meteorological data may be regarded as a novel. The results of the three homogeneity tests (Buishand, Pettitt, Standard Normal Homogeneity Test) show that 89.59 % of stations registered a change point for the two indices (SPI and RDI) time series in the three time scales (3, 6, and 12 months). The Mann–Kendall test showed a significant decreasing trend over all the stations. More stations have a significant decreasing trend with RDI than with SPI. Sen’s slope values are greater for SPI than RDI. The spatial distribution and the magnitude of the drought trend increased from East to West, which was more visible at the 3-month scale for the two drought indices. Groundwater recharge has been influenced by these downward trends over the last three decades. Researchers and policymakers involved in water resource management and agriculture should consider this fact, and these trends for improved planning and integrated governance of water resources in order to improve climate resilience.