Climate change poses major challenges for water resources and agriculture in Australia, a continent characterised by high interannual rainfall variability and competing pressures on water resources. Reliable, accessible climate information is critical for adaptation planning across multiple sectors, including water resources and agriculture. Climate projections are typically distributed in formats (e.g., NetCDF) and at spatial scales that are not readily usable by non-expert decision makers. To address these challenges, we produce deliberately simple, catchment-scale climate datasets for 245 Australian river basins, combining historical observations with high-resolution downscaled CMIP6 projections from global gridded products. For the historical period (1960–2023), we provide catchment-averaged annual rainfall (P), potential evapotranspiration (PET), the aridity index (P/PET), and mean temperature, all derived from the SILO database. Projections are provided for near-term (2021–2040) and mid-term (2041–2060) horizons under three Shared Socioeconomic Pathways (SSP2-4.5, SSP3-7.0 and SSP5-8.5). We provide a curated ensemble of Global Climate Models that adequately represent Australian climate dynamics. Outputs are provided as both raw projected values and as changes relative to a 1986–2005 reference period and are distributed in tabular (spreadsheet) and graphical formats to suit a range of users. We illustrate the application of these datasets through case studies in northern Australia (Port Hedland Coast (WA), Daly River (NT), and the Gilbert River (Qld), and southern rivers (The Swan Coast (WA), Millicent Coast (SA/Vic), and The Ovens River (Vic)). The datasets support rapid, first-pass climate risk assessment for water resources, agricultural and environmental planning. To further facilitate decision-making, the workflow can additionally be applied to user-supplied shapefiles.

This work was completed as part of the CRC for Developing Northern Australia Water Security Program, CRCNA project no: AT.7.2223014. See report Investigation of multi-catchment climate change models - modelling impacts over Northern Australia, by Dylan Irvine, Frederique Mourot, Lindsay Hutley, Paula Cartwright, and Nathan Waltham, 2026.

Dataset will be updated when the final reports are released.