Weather Changes: Condensation can be a seasonal or a night-time event. When outside temperatures are warm, the glass temperature will usually be above the dew-point. The same is true during cold, winter months.
Moisture Between Panes: Moisture that builds up between the panes of glass may be due to a failed insulating unit, and if so it should be repaired.
Window Size: Larger windows may have a higher tendency to show condensation.
Window Location: Minor differences in conditions can cause condensation to form on one window and not another, even when they are side-by-side. Windows protected from the wind will have a higher tendency to show condensation.
Air Circulation: Good air circulation, such as exposure to wind, reduces the occurrence of condensation. Building projections, foliage and other wind-breaks may contribute to condensation.
Screens: Windows protected by exterior screens may have different condensation than the same windows without screens under the same conditions.