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The seismicity of the Salton Trough area over the past 2,000 years has been linked to the repeated flooding of Lake Cahuilla, whose modern successor is the Salton Sea, suggesting that the lake's water content may have triggered seismicity through the propagation of pore pressure. In this paper, earthquake data since 1900 are analyzed to compare this hypothesis with the alternative that seismicity is triggered by groundwater recharge. Statistical methods were used to assess the degree of time correlation between the occurrence of Mw≥5.7 earthquakes, Salton Sea level fluctuations, and subsurface water recharge, using the Palmer Drought Severity Index (PDSI) as a proxy. The results show that only PDSI correlates well with seismicity, indicating that groundwater recharge should be preferred over Salton Sea level rise as a possible triggering factor. In particular, the drastic drop in seismicity over the past 38 years (just one earthquake compared to 14 in the previous 88 years, averaging one every 6.3 years) may be related to the series of extreme drought phases of the last few decades, particularly to the megadrought of 2000-2021. A similar correlation applies to the rest of Southern California, leading to the postulation of large-scale processes that act beyond strictly local climate and geological conditions. The statistical result is not sufficient to prove a causal relationship, but it may help guide further investigations. It suggests focusing on mechanisms related to the infiltration of meteoric water at depth rather than on water accumulation in the lake.