Static shocks are much more prevalent at this time of year due to the low humidity. At zero degrees Celsius (and below) the air cannot hold any moisture, and as a result any dampness which would otherwise prevent static build-up, is not present.
Although the type of material worn or that within the surroundings can exacerbate static generation – it can be difficult to eliminate.
To those who suffer shocks when alighting from a vehicle – grab hold of something conductive (a door frame, even the ignition barrel) while exiting. Any static will be dissipated as it is being generated – thereby avoiding the shock that occurs due to the sudden discharge of the charge that has been allowed to build-up.