Contributing factors to foggy windows include:
Water Exposure: Inspect your window seals following the flood or heavy rainstorm. Water surpluses around your windows might damage your perimeter seals, which allows moisture in.
Excess Heat: In double-paned windows, warm air stretches the seals. Chances are that most hot summer days will not pose a problem, but long exposures to direct sunlight can degrade your window seals over time.