This dataset contains: 1. The GIS boundaries of the 525 U.S. National Wildlife Refuges (refuges) analyzed. Refuges are constrained to the lower 48 states due to availability of climate data 2. A table of the full names of the 525 refuges and whether each refuge was buffered prior to analysis. For 107 refuges that were 0.01–4.9 km2 (median 1.4 km2) in size or that encompassed marine areas where we did not have projections (e.g., Oregon Islands National Wildlife Refuge), we first buffered the refuge by 2.5 km, an ecologically reasonable area for vagile birds to be using, before summarizing projections (see data repository for refuge buffer status).