Thermal Spring Season Timing Variability Indices Across Finland from 1961 to 2023

This dataset includes CSV files and raster files in TIFF (.tif) format, supporting the analyses and findings reported in the article published in Atmospheric Research (https://doi.org/10.1016/j.atmosres.2026.108752). The files represent data generated in the study, covering various spring timing indicators across Finland. Detailed information on data processing methods, analyses, and interpretations can be found in the associated manuscript. Additional metadata and file-specific descriptions are provided in the accompanying README.md file. Raster Files Include: Long-term averages (1961–2023) of Spring Season Onset dates (SSO), Spring Season End dates (SSE), Spring Season Duration (SSD), and the Growing Season Start dates (GSO), at 1 × 1 km spatial resolution across Finland. Z-scores of trends (1961–2023), derived from the Mann-Kendall test, for SSO, GSO, SSE, and SSD, at 1 × 1 km resolution across Finland. Sen's slope estimates (1961–2023) for trends in SSO, GSO, SSE, and SSD, at 1 × 1 km resolution across Finland. Spatial Reference System: EPSG:5048 — ETRS89 / TM35FIN (N,E) CSV Files Include: Time series of the first three principal components (PCs) derived from empirical orthogonal function (EOF) analysis of spring season onset dates, end dates, centroid dates, and duration from 1961 to 2023. Grid values of the first three EOFs for all spring timing indices, along with each grids’s latitude, longitude, distance from the sea, and elevation. Area-averaged time series for each spring timing index within each cluster from 1961 to 2023.