page_title: Tropical cyclone rainfall climatology
section_title: United States tropical cyclone rainfall statistics
hierarchical_section_title: Tropical cyclone rainfall climatology / United States tropical cyclone rainfall statistics
caption_attribution_description: English: David Roth, Hydrometeorological Prediction Center, Camp Springs, MD, USA http://www.wpc.ncep.noaa.gov/tropical/rain/tcduration.html
context_page_description: A tropical cyclone rainfall climatology is developed to determine rainfall characteristics of past tropical cyclones. A tropical cyclone rainfall climatology can be used to help forecast current or upcoming tropical cyclone impacts. The degree of a tropical cyclone rainfall impact depends upon speed of movement, storm size, and degree of vertical wind shear. One of the most significant threats from tropical cyclones is heavy rainfall. Large, slow moving, and non-sheared tropical cyclones produce the heaviest rains. The intensity of a tropical cyclone appears to have little bearing on its potential for rainfall over land, but satellite measurements over the last several years show that more intense tropical cyclones produce noticeably more rainfall over water. Flooding from tropical cyclones remains a significant cause of fatalities, particularly in low-lying areas.
context_section_description: Between 1970–2004, inland flooding caused a majority of the tropical cyclone-related fatalities in the United States. This statistic changed in 2005, when Hurricane Katrina's impact alone shifted the most deadly aspect of tropical cyclones back to storm surge, which has historically been the most deadly aspect of strong tropical cyclones.
  On average, five tropical cyclones of at least tropical depression strength lead to rainfall across the contiguous United States annually, contributing around a quarter of the annual rainfall to the southeast United States.  While many of these storms form in the Atlantic basin, some systems or their remnants move through Mexico from the Eastern Pacific basin.  The average storm total rainfall for a tropical cyclone impacting the lower 48 from the Atlantic basin is about 16 inches (406 mm), with 70–75 percent of the storm total falling within a 24-hour period.  The highest point total was seen during Hurricane Harvey in 2017, when 60.58 inches (1,538.7 mm) fell in southeast Texas.
caption: U.S. Tropical Cyclone Rainfall Accumulations per time frame
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