Global climate change and habitat loss are displacing tropical montane forests along mountain slopes1–4. Cloud forests are one of the most diverse and fragile of these montane ecosystems5–8, yet little is known about the historical and ongoing impacts of anthropogenic disturbances on these forests. Here we assess historical (1901–2016) changes in the altitudinal range of vascular plant species in Mesoamerican cloud forests and evaluate the relative impacts of climate change and land-use alterations. By analysing thousands of occurrence records from public biological collections, we uncovered common altitudinal shifts across species and suggest an overall contraction of cloud forests starting in the late 1970s. We infered a pervasive and interrelated impact of rising temperatures, changing precipitation patterns, and deforestation on the distribution of cloud forest species across Mesoamerica. Over the last fifty years, cloud forests have declined due to deforestation and warmer and more (seasonally) arid climates9–11. This is pushing species’ to contract their altitudinal ranges and may lead to an increasing probability of abrupt and devastating declines of population sizes, local adaptation, and migration.