Science Inventory

Projected Change in Climate Normals for Alaska, Hawaii, Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam and Commonwealth of the Northern Mariana Islands

Citation:

Jalowska, A. AND E. Horrigan. Projected Change in Climate Normals for Alaska, Hawaii, Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam and Commonwealth of the Northern Mariana Islands. U.S. Environmental Protection Agency, Washington, DC, 2025. https://doi.org/10.23719/1532430

Impact/Purpose:

The communities within “outside of the contiguous US” (OCONUS) are vulnerable to changing environmental conditions and associated risks to health, safety, and cultural assets. This research project provides information about the future changes in climate normals to five geographic areas: Alaska, American Samoa, Guam and Northern Mariana Islands, and Hawaii to support effective adaptation and resilience measures, thereby reducing the effects of extreme weather and changing environmental conditions. Final maps available at https://enviroatlas.epa.gov/enviroatlas/interactivemap/

Description:

This EnviroAtlas dataset contains projected change in 30-year normals in maximum temperature, minimum temperature, evapotranspiration, and precipitation, for Alaska, Hawaii, Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam and Commonwealth of the Northern Mariana Islands. This dataset was created using the NASA Earth Exchange-Global Daily Downscaled Projections (NEX-GDDP), developed using Global Climate Models (GCMs) runs conducted under the Coupled Model Intercomparison Project Phase 6 (CMIP6) across four scenarios, known as Shared Socioeconomic Pathways (SSPs). The four SSPs involved in this project are SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5. The raw NEX-GDDP-CMIP6 data has a spatial resolution of 0.25 degrees and a daily temporal resolution. The NEX-GDDP-CMIP6 data was processed to calculate projected changes in six climatic variables for each season (fall, spring, summer, winter) and annually for five 30-year periods: recent history (1976-2005) to near-term future (2025-2054) recent history (1976-2005) to mid-century (2045-2074) recent history (1976-2005) to end-of-century (2070-2099) near-term future (2025-2054) to mid-century (2045 to 2074) near-term future (2025-2054) to end-of-century (2070 to 2099) The six climatic variables included in the dataset are change in: total precipitation [in and fraction] total potential evapotranspiration [in and fraction] maximum temperature [degF], and minimum temperature [degF]. This data was then used to produce an NEX-GDDP-CMIP6 ensemble median for each variable for each HUC12. Not all GCMs downscaled in NEX-GDDP-CMIP6 had availability for every variable and scenario combination. Due to low historical values in precipitation and potential evapotranspiration, the data for Alaska is not available in fraction unit. Datasets will be available at https://enviroatlas.epa.gov/enviroatlas/interactivemap/ This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States.