A standardized permafrost ground temperature collection for Canada 2025

Abstract. Ground temperature is an essential variable for monitoring the thermal state of permafrost, developing models, and conducting fundamental research. However, the usability of GT data in Canada is often hampered by inconsistent file formats, a lack of metadata standardization between organizations, and varied temporal resolutions. This fragmentation has prevented the development of a comprehensive benchmark dataset, leaving researchers reliant on small, ad-hoc data subsets for model evaluation. To address this gap, we present a new, standardized collection of ground temperature (GT) and ground surface temperature (GST) data from across Canada, designed to serve as a benchmark for synthesis and model evaluation. The collection integrates data from 29 published datasets and 13 unpublished contributions, encompassing 427 GT and 491 GST sites across British Columbia, Labrador, Northwest Territories, Nunavut, Québec, and Yukon. All included time series feature at least one year of measurements at daily resolution. We performed quality control and standardization using tempcf — a newly-developed python software tool — to document and remove anomalies, outliers, and drilling disturbances. Then we aggregated sub-daily data to daily means. The dataset is standardized into NetCDF files adhering to CF, ACDD, and IOOS metadata standards as well as a compatible permafrost-specific metadata profile. Data are provided as both individual NetCDF files and text files. They are fully accessible at https://doi.org/10.5281/zenodo.18022925 (Meier-Legault et al., 2025) and via an ERDDAP server (data.permafrostnet.ca/erddap), following FAIR principles. Several limitations remain, including time zone uncertainty in some datasets, and the lack of a standardized methodology for harmonizing site description metadata. Nevertheless, this collection improves the accessibility and usability of Canadian ground temperature data for national-scale permafrost research.