El Niño Southern Oscillation (ENSO) is a recurrent climatic event that causes severe weather shocks. This paper employs ENSO-related floods at the end of the agricultural season to identify medium-term effects of negative conditions in early child development. The analysis shows that, four to five years after the shock, children exposed during
their early stages of life have test scores in language development, working-memory, and visual-spatial thinking abilities that are 11 to 21 percent lower than same aged children not exposed to the shock.

Negative effects are also found on anthropometric characteristics: children affected during their early life stages exhibit lower height (0.42 to 0.71 inches), higher likelihood of stunting (11 to 14 percentage points), and lower weight (0.84 pounds) than same aged children not affected by the shock. Negative effects of weather shocks on income, food consumption, and diet composition during early childhood appear to be key mechanisms behind the impacts on children’s outcomes. Finally, no mitigation effects were found from the provision of the Mexican conditional cash transfer program Progresa on poor rural households with children exposed to ENSO-related weather shocks."