This metadata record serves as documentation for the authoritative version of the CONUS404 atmospheric forcing dataset. CONUS404 is an abbreviated description for the original 40-year dataset: CONtiguous United States for 40 years at 4-kilometer grid spacing; however, the dataset has been revised to now include 43 years of data. This is a dataset of historical conditions (water years 1980-2022, October 1, 1979-September 30, 2022) and has sufficient temporal and spatial detail to resolve mesoscale atmospheric processes, making it appropriate for forcing hydrological models and conducting meteorological analyses. The dataset is the output of the Weather Research and Forecasting (WRF) v 3.9.1.1 model (Skamarock and others, 2008), forced with ERA5 reanalysis data (Hersbach and others, 2020), and consists of time series of nearly 200 2-dimensional variables and a wide range of 3-dimensional variables. Three sets of files were produced at different temporal resolutions: (1) 376,944 hourly files with all model outputs (files contained in wrfout directory), (2) 15,706 daily files containing data at 15-minute increments for precipitation and 2-meter temperature (files contained in auxhist24 directory), and (3) 15,706 daily files with minimum, maximum, and average values of a selection of surface variables (files contained in wrfxtrm directory). The Entity and Attribute element of the metadata record documents data dictionaries for all the variables in each of the three types of output files. These data dictionaries are attached to this data release. The output files are approximately one petabyte (1 PB) in volume and are being archived on the U.S. Geological Survey's Black Pearl tape drive system. The data can be accessed through a Globus access portal here: https://app.globus.org/file-manager?origin_id=12aeed7a-9693-4f99-9816-96911c1322d2&origin_path=%2F&two_pane=true. Please refer to the Supplemental Information element of this metadata record for further information on CONUS404.