Natural disasters related to hydro-meteorological events have increased during the last few decades, both in frequency and severity. Mexico is heavily exposed to climate change, but has also suffered in the past from climate variability (Blümel, 2009). The new risks oblige the government to develop mitigation processes, while the affected people are implementing strategies of adaptation and resilience-building, mostly at the family and community level. This includes forced migration due to climate change into the slums of megacities or illegal immigration to the United States. The arid, semi-arid and subhumid condition of 49.2 per cent of the territory of Mexico is seriously affected by climate change. In addition, poverty and the lack of jobs have created complex livelihood situations, in which young people leave rural areas, partly due to socio-economic pull factors. In this paper, we address the functional relationships between climate patterns and migration processes in Mexico, highlighting the linkages between the origin of migrants, their economic activity and their vulnerability to extreme events and we discuss long-term climate patterns. Agriculture still uses 78 per cent of the available water in Mexico. In the drylands the competition for water use requires an integrated policy to deal with the new threats from climate change, including mitigation from the top down and adaptation processes from the bottom up to reduce the social vulnerability of the rural population in the highly affected drylands of the central and northern parts of Mexico. The new policy for administering water resources, which promotes the efficient use of an increasingly scarce and polluted resource, still suffers from a lack of participation by the affected rural population. In this paper, we propose an integrated management system from the watershed onwards, involving socio-economic, political, cultural and hydrological variables, to deal with the rising scarcity of water, and the uncertainty and complexity of climate change.