Recent Trends in Agriculturally Relevant Climate in Central America

Abstract

This study examines the climatology and trends in climate in Guatemala, Honduras, and El Salvador over the past four decades, against the background of potential impacts on rainfed agriculture, livelihoods, and migration. The results show that there has been a significant warming of surface temperatures, an earlier start to the monsoon, a drier and longer mid-summer drought, and a delay in the second peak of precipitation from September to October. These changes have led to an increase in vapor pressure deficit (VPD) in northern Guatemala and along the Pacific coast in winter. High VPD can stress plants and lead to reduced yields. The study also finds that the thresholds that cause a decline in coffee yield have already been reached in El Salvador, but the average VPD has also risen in Guatemala and Honduras over the past 42 years. Maize yields have also been negatively affected with an inverse relationship with daily maximum temperatures during the summer flowering season. Observed changes and trends in these climate factors are believed to have direct implications for crop yields and livelihoods, potentially driving shifts in migration patterns.