Fuel tank (1) having: a wall (12) defining an internal volume (20) of the tank, and a temperature sensor (4) located inside the internal volume of the tank and at least partially enveloped with a material (21) having a thermal diffusivity comprised between 2×10−7 and 2×10−5 m2/s at 20° C. The temperature sensor measure an internal tank temperature, such as a vapor dome temperature.