1988–90 North American drought
At its peak, the drought covered 45% of the United States in 1988 alone. That's less area than the Dust Bowl, which covered 70% of the United States. But the Drought of 1988 caused $60 billion in damage. That not only is the most expensive drought in the history of the United States, it was the costliest natural disaster before Hurricane Katrina seventeen years later.