Hurricane Harvey has brought unprecedented rainfall since making landfall late Friday. The Houston suburb of Cedar Bayou had, by yesterday, seen nearly 52 inches of rain in roughly four days, the most rainfall in the continental United States during a single storm, according to the National Weather Service.
For perspective, It rains about 18 inches a year at Sacramento Executive Airport, according to the National Climatic Data Center, meaning that it usually takes three years for Sacramento to see 52 inches of rain.
Sacramento has been in a drought for much of the last decade, but large storms still occurred, especially in the last year. The biggest four-day storm total for Sacramento happened in early January 2017, when nearly 5.5 inches of rain fell in Sacramento.
Imagine that storm dropped 10 times more rain and you get near the equivalent of the rainfall Houston has seen since Harvey struck.