A set of Python-based tools, WRF4PALM, has been developed for offline nesting of the PALM model system 6.0 into the Weather Research and Forecasting (WRF) modelling system. Time-dependent boundary con- ditions of the atmosphere are critical for accurate repre- sentation of microscale meteorological dynamics in high- resolution real-data simulations. WRF4PALM generates ini- tial and boundary conditions from WRF outputs to pro- vide time-varying meteorological forcing for PALM. The WRF model has been used across the atmospheric sci- ence community for a broad range of multidisciplinary ap- plications. The PALM model system 6.0 is a turbulence- resolving large-eddy simulation model with an additional Reynolds-averaged Navier–Stokes (RANS) mode for atmo- spheric and oceanic boundary layer studies at microscale (Maronga et al., 2020). Currently PALM has the capabil- ity to ingest output from the regional scale Consortium for Small-scale Modelling (COSMO) atmospheric predic- tion model. However, COSMO is not an open source model and requires a licence agreement for operational use or academic research (http://www.cosmo-model.org/, last ac- cess: 23 April 2021). This paper describes and validates the new free and open-source WRF4PALM tools (available at https://github.com/dongqi-DQ/WRF4PALM, last access: 23 April 2021). Two case studies using WRF4PALM are pre- sented for Christchurch, New Zealand, which demonstrate successful PALM simulations driven by meteorological forc- ing from WRF outputs. The WRF4PALM tools presented here can potentially be used for micro- and mesoscale studies worldwide, for example in boundary layer studies, air pol- lution dispersion modelling, wildfire emissions and spread, urban weather forecasting, and agricultural meteorology.