Climate Change Projections for Mexico in the 21st Century

ABSTRACT Climate change projections for Mexico remain subject to substantial regional and inter‐model uncertainty, particularly for precipitation. Here, we assess 21st‐century changes in temperature and precipitation over Mexico using 36 CMIP6 models under four Shared Socioeconomic Pathways (SSP1‐2.6, SSP2‐4.5, SSP3‐7.0 and SSP5‐8.5). Model performance was evaluated against CRU and ERA5 for 1981–2000 using the Taylor Skill Score, and the five best‐performing models were selected to construct a primary multimodel ensemble. Projections from this selected ensemble were compared with those from the complete 36‐model ensemble to evaluate the influence of historical model performance on projected climate signals and uncertainty. Results show robust warming across Mexico under all scenarios, with national mean temperature increases reaching approximately 1.7°C under SSP1‐2.6 and 4.9°C under SSP5‐8.5 by 2081–2100. Warming intensifies with radiative forcing, is generally stronger over northern Mexico, and exhibits high inter‐model consistency. In contrast, precipitation shows greater temporal, spatial and inter‐model variability. National precipitation remains comparatively stable under SSP1‐2.6 but progressively declines under higher‐forcing scenarios, with widespread drying projected across southern and southeastern Mexico. Seasonal analysis indicates that this annual drying signal is primarily associated with reductions during the wet season, whereas dry‐season changes remain comparatively small and heterogeneous. The selected and complete ensembles produce similar large‐scale temperature and precipitation patterns, but historical model selection reduces inter‐model spread and areas of low agreement, particularly for precipitation. Overall, our results show that future climate change in Mexico will be characterized by robust and spatially coherent warming, together with a more uncertain but progressively stronger drying tendency, particularly during the wet season.