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 the average length of heat waves in days (duration), based on NOAA 2021 and Habeeb et al. 2015. These statistically insignificant data were analyzed from 1961 to 2021 for 50 large metropolitan areas. The size of each circle indicates the absolute change over the period. 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).