Decadal Trends in Streamflow and Stream Temperature across the Contiguous United States, Alaska, Hawaii, and Puerto Rico (1980–2020): Input Data and R Code

This data release contains the input data and R scripts to compile streamflow and stream temperature trend outputs (Hecht and others, 2024; Johnson, 2025), calculate Mann-Kendall and Theil-Sen slope trends for driver datasets (Konrad, 2020; PRISM Climate Group, 2014; USGS, 2024), and determine trend likelihood categories and associated driver correlations. The dataset includes 7,655 stream sites from the contiguous United States, Alaska, Hawaii, and Puerto Rico.
Trend results are provided for the following metrics:

Streamflow: Annual mean, annual maximum and minimum 7-day means, and monthly means.
Stream Temperature: Annual mean, annual maximum of 7-day average daily maximums, annual minimum of 7-day average daily minimums, and monthly means.
Driver Datasets: Annual and monthly means.

Trend and driver datasets are available across three fixed trend periods: 1980-2020, 1990-2020, and 2000-2020. This dataset includes several files in the “seasonal-trends.zip” folder containing scripts for data acquisition, basin delineation, and statistical analysis, as well as the final output files in "trends_outputs.csv" and "driver_correlation_outputs.csv". An analysis of these data is available in Stagnitta and others (2026).