In cold weather leaving the battery on the ground, especially concrete, will cause it to freeze quicker. Yes electrolyte does freeze. The lower the battery voltage the quicker it will freeze as well.
In a high humidity environment leaving a battery on the ground is "suppose" to cause it to drain/discharge quicker. However there is no proof it is because it is from the contact with the gound and not just condensation between the two battery posts. (i.e. the more logical explanation)
