Released in 2014, the NSW/ACT Regional Climate Modelling (NARCliM1.0) project produced high-resolution climate projections for three 20-year periods (1990-2009; 2020-2039; 2060-2079) over south-eastern Australia. It has since been applied widely in, for example, climate impacts and process research, climate adaptation, risk management, species distribution changes, and infrastructure planning. In early 2020, an enhanced dataset will be released by NSW government, namely NARCliM1.5. NARCliM1.5 includes 150-year (1950 – 2100) projections for two Representative Concentration Pathway (RCP) future scenarios, RCP4.5 and RCP8.5. Three global climate models (ACCESS1.0, ACCESS1.3 and CanESM2) from the Coupled Model Intercomparison Project phase 5 (CMIP5) suite have been dynamically downscaled using two Weather Research Forecasting (WRF) configurations at 10 km resolution over southeastern Australia.

Here we present a model evaluation across both NARCliM1.0 and NARCliM1.5 that focuses on temperature and precipitation – the most accessed variables in regional climate modelling datasets by both technical and non-technical users. We compare the mean and extreme distributions of modelled variables with available observations on regional and city scales within the NARCliM domain, for the overlapping 1990 – 2009 period. This NARCliM model evaluation for the 1950 - 2100 period demonstrates the complementary use of multi-generational regional climate model datasets. We conclude with guidance on the use of bias corrected and non-bias corrected data for a variety of non-research applications and describe the upgrades to the public accessibility of NARCliM1.0 and NARCliM1.5 in various data formats.