Definition of "hyperarid" []

• Extremely arid, with an aridity index of less than 0.05. (adjective)

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• "These include geological formations of notable interest as scenery and as the record of a fossil hydrographic system from fluvial to hyperarid conditions; and wildlife which includes 28 plant species rare in Algeria; one, the rare endemic cypress Cupressus dupreziana, being one of twelve critically endangered plants chosen by the Species Survival Commission of the IUCN to highlight serious threats to species around the world."
• "The plateau is hyperarid, very exposed and barren, but there are sheltered more humid microclimates where relict Mediterranean fauna and flora survive."
• "During that period there were roughly four glacial cycles and, although Egypt itself was ice-free, the local climate oscillated from hyperarid to semi-arid as the Earth's orbital position drove changes in the location of the tropical rainfall belts."