Several waves of slow-moving storms dumped record-breaking rains over parts of Middle Tennessee on Saturday, August 21, 2021, resulting in catastrophic flooding in which at least 22 people lost their lives and dozens remain missing. The worst impacted counties include Dickson, Hickman, Houston, and Humphreys.

From 00:00 to 20:30 CDT on August 21, the town of McEwen in Humphreys County received 432.3 mm (17.02 inches) of rain1, breaking the state's all-time 24-hour rainfall of 345.44 mm (13.60 inches) set in Milan on September 13, 1982. The value is still preliminary.

One of the worst-hit areas was Waverly (population 4 500), located just west of McEwen and about 120 km (75 miles) W of Nashville, where floodwaters gushed in at very high speed, leaving homes and buildings under 2 m (7 feet) of water.