In Salah or officially Aïn Salah () is the oasis town in central Algeria that is the capital of the In Salah Province and In Salah District. It was once an important trade link of the trans-Saharan caravan route. As of the 2008 census it has a population of 32,518, up from 28,022 in 1998, with an annual growth rate of 1.5%, the lowest in the province. The village is located in the heart of the Sahara Desert region of northern Africa. The name In Salah comes from the term "good well". Geography A creeping sand dune on the western edge of town is advancing on the city and cuts In Salah in half. The dune is moving at a speed of approximately one meter (three feet) every five years. As buildings are covered by its leading edge, structures at the back of the dune are being gradually uncovered. When a formerly covered location at the back of the dune once again becomes free, it is established who the past owners were and the building is restored and moved into by relatives. Four red or violet clay brick ksour (walled villages) are found in the oasis, each having its own citadel. Climate In Salah has a hot desert climate (Köppen climate classification BWh), with long, extremely hot summers and short, warm winters, and averages just of rainfall per year. Summer temperatures are consistently high as they commonly approach but temperatures at night fall low enough to around . The high temperature of was registered on 29 July, 2018. Even in early May or in late September, daytime temperatures can easily soar to . The Sahara region of Algeria is the source of a scorching, sometimes dusty and southerly wind called the Sirocco which parches the plateaus of northern Algeria for up to 40 days and reaches the Tell coastal region for as many as 20 days. During winter, nights can be chilly and frost is by no means unknown but the days are pleasantly warm, sunny and dry. In Salah has recorded at least in every month of the year including January and December as the absolute records high temperatures are respectively and for these two months. The absolute records low temperatures are below the freezing point, with recorded in January and recorded in both February and December, although freezing temperatures are very rare and don't occur each year. Average