U.S. home prices soared in July by a record amount from a year earlier as buyers desperate for homes bid up prices amid a limited supply.

The S&P CoreLogic Case-Shiller 20-city home price index surged 19.9% in July compared with a year ago, the largest gain on records dating back to 2000. In 17 of the 20 cities, prices rose more quickly in July than in June. And prices reached all-time highs in 19 of 20 cities. The one exception was Chicago, where prices are just 0.3% below their 2006 peak.

Sales of new and existing homes have jumped this year, driven by low mortgage rates and a desire for more living space during the pandemic. Sales of existing homes are up 16% in the first eight months of 2021 compared with last year, and they're up 12% from the same period in 2019.

Phoenix, San Diego, and Seattle reported the biggest price increases, with Phoenix leading the nation for the 26th straight month.