Drought in southern Africa under present-day and future climates

The Cape south coast (all-year rainfall region) and southwestern Cape (winter rainfall region) of South Africa have in recent years been in the grip of extreme drought. Over these regions drought occurs in association with rain-bearing frontal systems following anomalously southerly tracks over the Southern Ocean from autumn through to spring. Three consecutive years of below-normal rainfall during 2015-2017 induced a water crisis in Cape Town. Severe water restrictions were in place by the autumn of 2018, when the risk existed for the city to run out of water. Although a normal winter rainfall season has subsequently largely replenished dam levels in the Cape Town region, severe drought conditions continue to persist further to the east along the Cape south coast. The potential attribution of these recently recorded severe droughts over the southern parts of South Africa to climate change is an active area of research. The observational record shows that similar droughts have occurred in Cape Town in the 1920s and 1960s, suggesting that the recent drought may well be the consequence of natural variability. However, significant warming has occurred over the region, leading to enhanced evaporation and an increase in high-fire days, with implications for worsening periods of agricultural drought. Climate change projections robustly indicate that frontal systems are to be displaced increasingly polewards in the Southern Hemisphere under climate change, implying the likelihood for shorter return periods of severe droughts along the Cape south coast and southwestern Cape regions of South Africa during the 21^st century.