This paper analyzes the impact of climate change on particulate air pollution and applies this exogenous causal effect to study the effect of air pollution on infant health. Using daily weather data, daily data on PM10 from 1990-2013 and daily data on PM2:5 from 1997-2013, I find the first causal estimates of the level of precipitation as well as the precipitation frequency on particulate matter concentrations in ambient air. I utilize information on Clean Air Act Nonattainment designations, to estimate differential impacts of lesser and infrequent precipitation on air pollution in non-attainment counties vs counties compliant with the federal regulations. I find that lower as well as less frequent rainfall will lead to larger concentrations of particulates in ambient air. The effects are even larger in non-attainment counties, potentially driven by the higher level of precursors and pollution sources. Using my findings, I exploit exogenous rainfall variation in an instrumental variables approach to also estimate the effect of increases in ambient particulate matter on the number of infant deaths. My estimates suggest that a 1 µg/m3 decrease in ambient PM10 concentrations would imply almost 27 fewer infant deaths per 100,000 live births