The deadly heatwave that scorched large swaths of Mexico, Central America and the southern US in recent weeks was made 35 times more likely due to human-induced global heating, according to research by leading climate scientists from World Weather Attribution (WWA).

Tens of millions of people have endured dangerous day – and nighttime temperatures as a heat dome engulfed Mexico – a large and lingering zone of high pressure that stretched north to Texas, Arizona and Nevada, and south over Belize, Honduras, Guatemala, and El Salvador.

A heatwave can be caused by several factors including a heat dome, which traps hot air close to the ground, blocking cool air from entering and causing temperatures to rise on the ground and stay high for days or weeks. In May and early June, the heat dome hovered over the region, breaking multiple daily and national records, and causing widespread misery and disruption, especially among the poorest and most marginalized communities.