The Middle Draa watershed is increasingly exposed to extreme climatic events, whose climate-related risks if inadequately managed may result in massive population displacement, ecological disasters, and critical shortages of water, food, and other essential resources. This study aims to examine the spatio-temporal variability of droughts along an arid gradient within the Middle Draa watershed (southeastern Morocco). Drought was characterized at four stations (Agdez, Zagora, Tagounite and M'hamid El Ghizlane) over 1989–2020 with the Standardized Precipitation Index (SPI), computed at 3-, 6-, 9- and 12-month scales from monthly precipitation totals by fitting a gamma distribution to each calendar month. Regardless of the time window examined, the analysis of the results reveals that the most severe and prolonged droughts occurred during the years 1999–2003 and 2005–2008. These drought episodes peaked in 2001 and 2003, reaching extreme levels of severity. The upstream stations (Agdez and Zagora) had the longest SPI-12 drought spells (18 and 17 months, against 11 and 13 months downstream), while cumulative severity at the 9- and 12-month scales was similar at all four stations. At the driest stations the 3-month SPI is bounded by the high frequency of rainless periods, so the 9- and 12-month scales describe drought more reliably there. Measured against local norms, drought therefore does not ease upstream, even though mean annual rainfall at Agdez (93.5 mm) is more than twice that at M'hamid El Ghizlane (39.2 mm). The Mann–Kendall test shows no significant trend in the 12-month SPI at any station (p ≥ 0.055). Because it rests on four stations, this pattern should be treated as a hypothesis to be tested with a denser network.