ADVANCED REVIEW Assessing precipitation trends in the Americas with historical data: A review Leila M. V. Carvalho Department of Geography, University of California, Santa Barbara, California Correspondence Leila M. V. Carvalho, Department of Geography, University of California, Santa Barbara, CA 93106. Email: leila@eri.ucsb.edu Edited by Sophie Lewis, Domain Editor, and Mike Hulme, Editor-in-Chief Abstract North, Central, and South America (collectively referred to as the Americas) extend across two hemispheres, and together cover approximately 28% of Earth's land area and are home to about 13% of the world's population. Unique ecosystems, diversi- fied cultures, and communities that inhabit the region rely on precipitation deliv- ered yearly by multiple systems, including mid-latitudes storms, the North and South American Monsoons, and tropical storms and hurricanes. The rapid warming of the Earth's atmosphere and oceans combined with internal variability of the cli- mate system, have modified precipitation patterns from the tropics to high latitudes. In the Americas, instrumental records have shown evidence of upward trends in extreme precipitation (amount, intensity, and frequency) in many areas. The most consistent evidence of precipitation trends occurs in mid-latitudes of North Amer- ica and in the subtropics of South America. Recent studies have indicated a pole- ward shift of heavy precipitation associated with South American Monsoon. Nonetheless, the deficient network of rain gauges in vast areas over tropical Ame- ricas limits the assessment of trends in regions with heavy rainfall amounts. Addi- tionally, observed trends in the North America monsoon precipitation are difficult to separate from the contribution of tropical storms and hurricanes. Furthermore, coupled modes such as the El Nino/Southern Oscillation, the Pacific Decadal Oscillation, and the Atlantic Multidecadal Oscillation modulate precipitation in the Americas, from the tropics to the extratropics, and these teleconnections are rele- vant to assess precipitation trends using historical records. This review evaluates all these complex issues focusing on observations based on instrumental datasets. This article is categorized under: Paleoclimates and Current Trends > Modern Climate Change KEYWORDS Central America, extreme precipitation trends, North America, precipitation trends, South America 1 | INTRODUCTION One of the most relevant, complex, and largely unknown impacts of global warming is the change in the spatiotemporal pat- terns of precipitation over land. The magnitude of these changes and how they will affect the distribution of precipitation (rain and snowfall) in continental areas will set the limits of water resources for billions of people and determine the fate of many ecosystems. Received: 11 November 2018 Revised: 23 September 2019 Accepted: 4 October 2019 DOI: 10.1002/wcc.627 WIREs Clim Change. 2019;e627. wires.wiley.com/climatechange © 2019 Wiley Periodicals, Inc. 1 of 21 https://doi.org/10.1002/wcc.627