Yes, it does snow in the Sahara, though rarely. On Sunday 7 January 2018, snow covered the orange sand dunes around Aïn Séfra, a town in north-western Algeria on the northern edge of the desert. Local photographer Zinnedine Hashas captured the white-and-orange landscape before most of it melted. On the dunes the snow lasted only a short time; on the surrounding Atlas Mountains it stayed longer.
The pictures travelled around the world because they look impossible. They are real, and the explanation is less mysterious than it seems: Aïn Séfra sits high, has cold winter nights, and occasionally finds itself under a blast of cold European air at the same moment as moist weather arrives.
Where and why it snowed in the desert
Aïn Séfra lies at about 1,000 to 1,080 metres above sea level, in a valley of the Saharan Atlas mountains, and was once nicknamed the gateway to the Sahara. Desert does not mean hot all year. The town has a cold desert climate: Wikipedia's climate table puts the average January high at about 14°C and the average January low at about 1°C, so frosty nights are normal in winter. Older versions of this story said the average January low was 12.4°C; that figure is far too warm for a winter night and is closer to a typical daytime high.
What is unusual is precipitation. The town receives only around 190 mm (about 7.5 inches) of rain and snow a year, below the roughly 250 mm (10 inches) threshold often used to define a desert. For snow to settle, cold air and moisture must arrive together.
That is what happened in January 2018. A UK Met Office spokesman, quoted by the Royal Meteorological Society, explained that high pressure over Europe pulled cold air south into North Africa over that weekend. When that cold air met moisture from a weather system over the western Mediterranean, the result was snow. Algeria's national weather service had warned of 10 to 15 cm of snow in the west of the country before the event.
How much snow fell, and how rare is it?
Reports disagreed about the depth. Some outlets, including the Royal Meteorological Society's summary, said the area received around 40 cm (15 inches). CNN reported that the town itself officially recorded less than an inch. Both can be partly true: snow drifts and higher ground hold far more snow than a weather station in town.
The event was widely described as the third snowfall in about 40 years at Aïn Séfra. Records show light snow on 18 February 1979, then snow again in December 2016, which also produced famous photos of snow-dusted dunes. Wikipedia's record for the town also notes snow in January 2017, and further snowfalls followed in 2021 and 2022. So “once every few decades” is no longer quite right; snow there is rare, but not a once-in-a-lifetime event.
The higher mountain areas of Algeria, such as the Djurdjura and Aurès ranges, see snow most winters. The surprise in Aïn Séfra is the contrast: snow lying directly on bright orange sand.
The photographs
Most of the images below were taken by Zinnedine Hashas around Aïn Séfra on 7 January 2018. A satellite view of the same day is available through NASA Worldview, which showed snow along the ridgelines east of the town.
A broad view across the dunes shows snow lying mainly on the upper slopes and crests, with sand exposed in the hollows. Wind shapes both the dunes and the way snow drifts across them, so the pattern follows the landforms.
Here the snow-covered peaks of the Atlas Mountains rise behind the desert scrub. The mountains kept their white cover longer than the sand, which warms quickly once the sun comes out.
A single dune ridge is coated in white while the orange sand on either side stays bare. Snow settled on the cooler, shaded side and along the crest, which is why one slope looks painted.
Under a heavy grey sky, the dune field looks almost like a northern winter landscape. Only the ripples of sand in the foreground give away the location.
Snow and sand form swirling bands across the slopes. Patterns like this last only a few hours, as melting starts on the sunniest faces first.
Low cloud clings to the mountains while the dunes below are almost fully white. Thin lines of sand show where the wind exposed the ridges.
Blue sky breaks through over a dune field streaked with snow. As the sun returned, the snow line began retreating up the slopes.
In the town itself, a light layer of snow covers gardens and open ground beneath palm trees and a minaret. Scenes like this, with palms and snow together, are a reminder that Aïn Séfra is an oasis town as well as a desert gateway.
A lone figure stands on top of a snowy dune as mist rolls over the hills. Many local residents went out to photograph the dunes before the snow disappeared.
Is this a sign of climate change?
A single snowfall cannot be linked to climate change on its own. Weather varies a great deal from year to year, and cold outbreaks still happen in a warming world. Scientists look at long-term trends across many years and stations before drawing conclusions. What these events do show is that the Sahara has always had a more varied climate than its image suggests, with freezing nights in winter and, very occasionally, snow.
For other unusual snow scenes, see our photo stories on winter in Oymyakon, Siberia.
Sources: Royal Meteorological Society, 9 January 2018: Snowfall in the Sahara Desert; CNN, 9 January 2018: Snow falls in the Sahara; Wikipedia: Aïn Séfra; Deutscher Wetterdienst climate data for Aïn Séfra; Météo Algérie warning; photographs by Zinnedine Hashas.
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