“ChesBay 24k – CL": Climate Related Data Summaries for the Chesapeake Bay Watershed Within NHD Plus HR catchments  (ver. 4.0, August 2025)

These tabular data are the summarization of climate related variables within catchments of the Chesapeake Bay watershed at the 1:24,000 scale using the xstrm methodology. Variables being counted as climate related include temperature and precipitation by both annual and monthly timesteps. Outputs include tabular comma-separated values files (CSVs) and parquet formatted files for the local catchment and network summaries linked to the National Hydrography Dataset Plus High-Resolution (NHDPlus HR) catchments by NHDPlus ID. Local catchments are defined as the single catchment within which the data are summarized. Network summaries are summaries for each of the local catchments and their respective network-connected upstream or downstream catchments for select variables. The summarized data tables are structured as a single column representing the catchment id values (i.e. NHDPlus ID) and the remaining columns consisting of the summarized variables. The downstream network summary type is not present within the dataset as no summaries were conducted using that summary type.
Additionally, for a full description of the variables included within these summaries see xstrm_nhdhr_climate_chesapeake_baywide_datadictionary.csv in the attached files.
The xstrm local summary methodology takes either raster or point data as input then summarizes those data by "zones", in this case the NHDPlus HR catchments. The network summaries then take the results from the local summaries and calculates the desired network summary statistic for the local catchment and its respective upstream or downstream catchments.
As a note concerning use of these data, any rasters summarized within this process only had their cells included within a catchment if the center of the raster cell fell within the catchment boundary. However, the resolution of the input raster data for these summaries was considered to provide completely adequate coverage of the summary catchments using this option. If a confirmed complete coverage of a catchment is desired (even if a raster cell only is minimally included within the catchment) then it is recommended to rerun the xstrm summary process with the "All Touched" option set to “True”.
These data were updated in September 2024, March 2025, and August 2025. Some changes during these revisions include the removal of several variables unnecessary to the use of the data summaries, the correction of calculated area variables and all dependent variables, and the addition of new variables to the dataset. See xstrm_nhdhr_climate_chesapeake_baywide_versionhistory.txt for further details.
Further information on the Xstrm summary process can be found at the Xstrm software release pages:
Xstrm: Wieferich, D.J., Williams, B., Falgout, J.T., Foks, N.L. 2021. xstrm. U.S. Geological Survey software release. https://doi.org/10.5066/P9P8P7Z0.
Xstrm Local: Wieferich, D.J., Gressler B., Krause K., Wieczorek M., McDonald, S. 2022. xstrm_local Version-1.1.0. U.S. Geological Survey software release. https://doi.org/10.5066/P98BOGI9.

Tags: air-temperature, chesapeake, delaware, district-of-columbia, geographic-information-systems, geoscientificinformation, geospatial-datasets, hydrographic-datasets, hydrology, inlandwaters, lower-chesapeake-bay, maryland, new-york, pennsylvania, precipitation-atmospheric, upper-chesapeake-bay, usgs-649462c3d34ef77fcb014edd, virginia, west-virginia
Organization: Department of the Interior