A rare deluge of rainfall left blue lagoons of water amid the palm trees and sand dunes of the Sahara Desert, nourishing some of its most drought-stricken regions with more water than many had seen in decades.

Southeastern Morocco’s desert is among the most arid places in the world and rarely experiences rain in late summer.

The Moroccan government said two days of rainfall in September had exceeded yearly averages in several areas that get an average of less than 250 millimetres (10 inches) annually, including Tata, one of the areas hit hardest. In Tagounite, a village about 450 kilometres (280 miles) south of the capital Rabat, more than 100mm (3.9 inches) was recorded in a 24-hour period.

The storms left striking images of bountiful water gushing through the Saharan sands amid castles and desert flora.

“It’s been 30 to 50 years since we’ve had this much rain in such a short space of time,” said Houssine Youabeb of Morocco’s General Directorate of Meteorology.

Such rains, which meteorologists are calling an extratropical storm, may indeed change the course of the region’s weather in months and years to come as the air retains more moisture, causing more evaporation and drawing more storms, Youabeb said.

Six consecutive years of drought have posed challenges for much of Morocco, forcing farmers to leave fields fallow and cities and villages to ration water consumption.

The bounty of rainfall will likely help refill the large groundwater aquifers that lie beneath the desert and are relied upon to supply water in desert communities. The region’s dammed reservoirs reported refilling at record rates throughout September. However, it is unclear how far September’s rains will go towards alleviating drought.

The sudden torrents of water gushing through the sands and oases left more than 20 dead in Morocco and Algeria and damaged the farmers’ harvests, forcing the government to allocate emergency relief funds, including in some areas affected by last year’s earthquake.

NASA satellites showed water rushing in to fill Lake Iriqui, a famous lakebed between Zagora and Tata that had been dry for 50 years.