Domestic grain trade connects geographically uneven production regions, processing centers, and demand markets through regional trade linkages. This paper examines whether U.S. county-level cereal grain trade is spatially interdependent and whether local trade intensity is associated with climate-related moisture conditions in nearby counties. Using a downscaled county-to-county trade network and spatial econometric models, the analysis shows that county-level imports and exports are geographically clustered rather than randomly distributed. Spatial dependence is more pronounced for exports than for imports, suggesting that export intensity is more closely tied to regional production clusters and neighboring trade activity. Growing-season SPEI, measured relative to historical norms, is also associated with trade intensity beyond local county boundaries. In particular, neighboring counties’ SPEI is negatively associated with local import and export intensity. Overall, the results suggest that domestic grain trade functions as a regional spatial system rather than a set of independent local markets, highlighting the importance of regional linkages in county-level grain trade.
