Shared Enterprise Geodata and Services (SEGS) provides an EPA-curated collection of recommended geodata assets that are nationally relevant and support the Agency’s mission to protect human health and the environment. By connecting EPA users with curated datasets and promoting service reuse, SEGS aims to enhance information access, reduce data-storage costs, and improve the consistency and quality of data at the US EPA.

Developed by the U.S. EPA Office of Air and Radiation, this content item depicts trends in the date during the year when snowpack reached its maximum across the western United States between 1982 and 2021, based on 2021 data from U.S. Department of Agriculture's Natural Resources Conservation Service (NRCS). Peak snowpack analysis was adapted from Evan 2019. Blue triangles represent a shift to later timing; red triangles represent a shift to earlier timing. For more information, please visit the U.S. EPA climate change indicators webpage. These data and their corresponding metadata records can be downloaded from the EPA Environmental Dataset Gateway (EDG).

Evan, A. 2019. A new method to characterize changes in the seasonal cycle of snowpack. J. Appl. Meteorol. Clim. 58:131–143