Migration provides a strategy for rural Mexican households to cope with, or adapt to, weather events and climatic variability. Yet prior studies on environmental migration in this context have not examined the differences between choices of internal (domestic) or international movement. In addition, much of the prior work relied on very coarse spatial scales to operationalise the environmental variables such as rainfall patterns. To overcome these limitations, we use fine‐grain rainfall estimates derived from NASA's Tropical Rainfall Measuring Mission satellite. The rainfall estimates are combined with population and agricultural census information to examine associations between environmental changes and municipal rates of internal and international migration during 2005–2010. Our findings suggest that municipal‐level rainfall deficits relative to historical levels are an important predictor of both international and internal migration, especially in municipalities with predominantly rainfed agriculture. Although our findings do not contradict results of prior studies using coarse spatial resolution, they offer clearer evidence and a more spatially nuanced examination of migration as related to social and environmental vulnerability. Copyright © 2017 John Wiley & Sons, Ltd.