The United Arab Emirates (UAE) straddles 22–26 °N, positioning it in a latitudinal band well known across the globe for its desert biomes. The UAE is characterized by arid to hyper-arid conditions, but with marked variation in precipitation seasonally (highest in winter/spring) and across locations (highest near the Hajar mountains), representing a dramatic shift from the more humid conditions that characterized this region just six millennia ago. The low cloud cover, limited vegetation and poorly developed soil also result in extreme and highly variable temperatures across the year, particularly in areas distant from the coasts. Winds are typically dominated by daily land/sea breezes, but occasional brief ‘shamal’ wind events (particularly in late winter) or cyclones (in early summer) can have important implications for temperature, rainfall and biotic responses. Average temperatures have increased by 1 °C between the 1980s and the 2010s, and rainfall has declined by more than half; in addition, wet bulb temperatures associated with human health are increasing, and may exceed life-threatening levels by the end of the century. Today’s climate represents extremely marginal conditions for life, and the current trends suggest that the already vulnerable ecosystems and organisms of the UAE are coming under increasing climate-related pressure.