Development of operational 0.01° resolution gridded historical daily precipitation data for Australia

Long-term gridded precipitation data are critical for better scientific understanding, environmental management and prediction of extreme events. We present the development and evaluation of daily 0.01° (~1- × 1-km) gridded precipitation data for Australia from 1880 onwards. The Australian Gridded Climate Data (AGCD) dataset is intended to replace the existing operational system. It employs statistical interpolation and is based on climatology for the 1981–2010 period and includes pseudo-observations. Performance evaluation was undertaken using 11 metrics and diagnostic plots, and analysis of daily totals, extreme events, intensity and weekly–monthly–seasonal–annual accumulation for the period 1990–2022. Results demonstrate that the ~1-km AGCD performs comparably to other products in the world. Preliminary comparison with Australian Water Availability Project 5-km resolution data demonstrated that AGCD products are more accurate and reliable. The Bureau plans to develop a fully automated operational system for delivering daily 1-km scale precipitation data.