This paper focuses on finite element modelling of temperature field in cylindrical grinding. The developed model is validated against two established and validated thermal models in cylindrical grinding. The models' results are compared in terms of suitability for a digital twin application. The computation time requirement for a real-time temperature estimator in grinding digital twin is defined. The FEM model offers the most fidelity, but computational demands prevent its use in a digital twin. Therefore, the need for coupling the FEM model with an AI-based approaches for future work is highlighted to achieve temperature estimation within the wheel contact time.