An experimental study has been carried out to reveal the statistical characteristics for the onset of micro-explosion of an emulsion droplet evaporating on a hot surface. The measurements are made of the waiting time for the onset of micro-explosion at various ambient pressures, base fuels, water contents and surface temperatures. The Weibull analysis is applied to obtain the distribution function of the waiting time for the onset of micro-explosion and to derive the empirical formula for the rate of micro-explosion as a function of the water volume and emulsion temperature. The results show that the waiting time is correlated well with the Weibull distribution of the wear-out type. The waiting time decreases with an increase in the ambient pressure, the saturation temperature of base fuel, the water content and the surface temperature. An empirical formula is proposed for the rate of micro-explosion as a function of the water volume and emulsion temperature.