Mist formation that occurs during production, handling, and transport of natural gas is shown to be the result of non equilibrium thermodynamic processes. A simple analysis is presented of these nucleation and droplet growth phenomena in natural gas, and an estimate is given of the rate at which droplets are formed for typical process conditions. A model of droplet growth due to condensation is presented. The nucleation and condensation behaviour of two samples of a natural gas is investigated in a Wilson expansion cloud chamber for the initial pressure range of 5 to 50 bar and initial temperatures of 294-297 K (21-24-degrees-C). For a cooling rate of about 1 K/ms, a typical undercooling at the onset of condensation is found of 32 +/- 3 K and 60 +/- 5 K respectively for the two samples, which emphasizes the importance of non-equilibrium effects.