Your Camera Could Be Too Cool
Summertime brings dreams of vacation on a beach, kids splashing in the water, and some great photos for the family album. You may have noticed that the humidity along a shore or coast line is very high, especially in the morning.
The way I keep my camera lenses from fogging when I take them from the air conditioned indoors to the scenic outdoors is to keep them outdoors. This may seem a bit dangerous but I lock my gear in my car in most cases. An alternate method is to put the camera outside on a guarded porch or a balcony first thing in the morning and waiting a hour or so for the lens to warm to the ambient temperature.
You'll need some good lens wipes because once the lens has warmed you may find some residue left by the evaporating water. You can also just shoot through the condensation and use your developing software to defeat the haze. That's what I did for this video.