The Leidenfrost transition of water droplets impinging onto a superheated surface

•Experiments are conducted on water droplets impinging on a sapphire surface heated up to 700 ∘C.•To characterize heat transfer, temperature of the solid surface is measured by IR thermography, and droplet temperature is determined by two-color laser-induced fluorescence imaging.•The dynamic LFP (Leidenfrost point) corresponds to the initial wall temperature for which the solid surface is cooled down to the temperature of the spinodal during the impact process.•Above the LFP, fingering boiling is observed while the liquid at the interface with the vapor film remains in a very high level of superheating.•The superheat of the liquid is an essential parameter for the modelling of heat transfer between liquid and solid surface in the film boiling regime.