Rising Hourly Rainfall Intensity

Analysis of 150 U.S. weather stations shows that 91% experienced an increase in hourly rainfall intensity between 1970 and 2022, with an average increase of 13%. This trend is linked to climate warming, which allows the atmosphere to hold more moisture, increasing the risk of flash flooding and landslides regardless of whether a location is typically wet or dry.

• Between 1970 and 2022, 136 out of 150 analyzed U.S. weather stations (91%) saw an increase in hourly rainfall intensity, with an average increase of 13% across all stations.
• Hourly rainfall intensity increased across all nine analyzed U.S. regions, with the most significant average increases occurring in the East North Central (+19%), West North Central (+18%), Central (+16%), Southwest (+14%), and Northeast (+13%) regions.
• The increase in rainfall intensity is widespread and affects both wet and dry areas; seven of the ten locations with the highest intensity increases are below the national average annual precipitation of 31.3 inches.
• The intensification of rainfall is driven by thermodynamics: for every 1°F of warming, air can hold 4% more moisture. Since the U.S. has warmed approximately 2.5°F since 1970, the atmosphere can hold about 10% more moisture, increasing the likelihood of heavy downpours.
• Intensifying rainfall has significant economic and social impacts, accounting for one-third of nationwide flood damages (approximately $73 billion) between 1988 and 2017. Vulnerability is higher for racial minorities and those in mobile homes, particularly in rural areas and the southern U.S.

APA

Duque, F. Q., Mesa, G. J. P., Dougherty, E., & Wright, D. (2023). Rising Hourly Rainfall Intensity. Climate Central. https://www.climatecentral.org/climate-matters/rising-hourly-rainfall-intensity-2023

Chicago

Duque, Felipe Quintero, Gabriel J Perez Mesa, Erin Dougherty, and Daniel Wright. Rising Hourly Rainfall Intensity. Climate Central, 2023. https://www.climatecentral.org/climate-matters/rising-hourly-rainfall-intensity-2023.

Wikipedia

{{cite report |last1=Duque |first1=Felipe Quintero |last2=Mesa |first2=Gabriel J Perez |last3=Dougherty |first3=Erin |last4=Wright |first4=Daniel |title=Rising Hourly Rainfall Intensity |publisher=Climate Central |date=26 April 2023 |url=https://www.climatecentral.org/climate-matters/rising-hourly-rainfall-intensity-2023 |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{duque2023rising, author = {Duque, Felipe Quintero and Mesa, Gabriel J Perez and Dougherty, Erin and Wright, Daniel}, title = {{Rising Hourly Rainfall Intensity}}, institution = {Climate Central}, year = {2023}, month = apr, url = {https://www.climatecentral.org/climate-matters/rising-hourly-rainfall-intensity-2023}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }