In the Mexico City Metropolitan Zone (MCMZ) the wet atmospheric deposition is a problem with great environmental impact due to its potential effects on ecosystems and cultural heritage. The understanding of the atmospheric emissions and the meteorological conditions of the study area allows us to know which are the specific conditions that aggravate it and gives us a key tool to reduce it and thus protect the environment.

The objective of this study was to evaluate the influence of meteorological conditions on the wet atmospheric deposition in the MCMZ. The rain samples were collected by the Wet Atmospheric Deposit Network (REDDA) operated by SIMAT, in the period 2013-2016 and analyzed in the University of Mexico (UNAM) laboratory. Meteorological information was obtained from the Meteorology and Solar Radiation Network (REDMET) operated by SIMAT. The chemical analysis of the samples consisted in the determination of the parameters recommended by the NADP protocol, which are: pH, electrical conductivity, concentration of cations (Na⁺, NH₄⁺, K⁺, Mg²⁺, Ca²⁺) and anions (Cl⁻, NO₃⁻ and SO₄²⁻). The NH4+ was the ion with the highest concentration (μEq/L), while SO₄²⁻ present the highest deposition (kg/ha). The South region of the MCMZ showed the most acid pH. In addition, the relationships between the meteorological variables and the ion concentrations were analyzed by the Spearman correlation method, obtaining that the SO₄²⁻ (r=20) presented a greater contribution to the acidity of the rain and that the Ca²⁺ (r=38) contributed to the neutralization of acidic compounds. Likewise, the correlation showed that at higher temperature, the pH and ions concentration are higher, while to a greater precipitation and relative humidity, pH and ions concentration are lower. Through the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), it was identified that the zones of origin of the acid rain precursors are those of the north (N), north-northwest (NNO) and north-northeast (NNE). Finally, measures were proposed such as the use of fuels fossils with less sulfur in energy and industrial sectors both in and outside MCMZ, in order to prevent, minimize and control acid rain precursors.