GHCN-daily: Western United States precipitation dataset

This is a dataset of daily precipitation totals in the western United States (US) from January 1 1950 – February 29 2024. The dataset is based on daily precipitation measurements from 642 gauges across the western US, with periodic data gap-filling perfomed using estimates based on nearby gauges. From the daily records at the 642 gauge sites we produced a gridded record of daily precipitation totals at 0.25-degree resolution across the western US. The 642 gauges used as the basis for this dataset were selected for their uniquely long records and continuous coverage from the early 1950s through 2023. The purpose of producing this dataset was for evaluation of trends in sub-monthly cool-season (November–March) precipitation characteristics., Considering all daily gauge records available from the Global Historical Climatology Network-Daily (Menne et al., 2012) we first compile a master database of daily precipitation totals for the 3,528 gauges within a 1° buffer of our western US study area with valid data for ≥50% of days in each of ≥20 years during calendar years 1950–2023. We then perform an initial zero-filling procedure in which missing values are replaced with zero on days when all (and ≥2) other gauges with valid data within 50-km report no precipitation. When there are <2 gauges within 50 km with valid data, but at least two gauges within 100 km with valid data, the zero-filling is repeated if all available (and ≥2) gauges within 100 km report zero precipitation.
From this master database we identify 645 “primary gauges” within the boundaries of our western US study area with particularly thorough coverage over the study period of cool seasons (November–March) 1951–2023. Long data records are critical to our asse..., , # GHCN daily western United States precipitation

[https://doi.org/10.5061/dryad.c866t1gfp](https://doi.org/10.5061/dryad.c866t1gfp)

This dataset contains daily precipitation totals for the western United States (US) as represented by gauge data from Global Historical Climatology Network (GHCN) daily dataset.

## Description of the data and file structure

This dataset contains daily precipitation totals for the western United States (US) as represented by the Global Historical Climatology Network (GHCN) daily dataset. Components of the dataset are:

prec_daily.nc: This is a netcdf file file called prec_daily.nc with gridded 1/4-degree estimates of daily precipitation total from Jan 1 1950 – Feb 29 2024. There are 100 latitudes, from 28.125N to 52.875N and 108 longitudes, from 126.875W to 100.125W. There are 27,088 daily time steps, corresponding with a time vector with units of days since Jan 1 1800. Grid cells lying outside of the western US do not have values. Here, western US is de...