1. FAFK 5:30am: wind 0-2kts, temp 9deg, humidity 91%
2. FAFK 6:30am: wind 0-2kts, temp 7deg, humidity 93%
3. Reported dew point for Cape Town 7deg
4. Cape Town city bowl covered in thick fog, ships continously sounding fog horns
My conclusion: trend at FAFK, temp dropping to dew point, eventually reaching dew point, humidity increasing, fog everywhere else
there's gotta be fog at FAFK too. Decision: stay put at home and keep looking at the sky, try for the evening. 
WRONG!!! Turns out FAFK was open, guys were happily flying 
What did I do wrong?!
The definition of dew point is: "The dew point or dewpoint of a given parcel of air is the temperature to which the parcel must be cooled, at constant barometric pressure, for the water vapor component to condense into water." This is all cool, remembered from the met training. What I missed was the following: "The dew point is associated with the relative humidity. A high relative humidity indicates that the dew point is closer to the current air temperature. If the relative humidity is 100%, the dew point will be equal to the current temperature."
So there we go - humidity was not 100% therefore the 7 deg warm parcel of air above FAFK had no reason to condense into fog and I should have came up with a better excuse for my laziness ...
Right now rain has just stopped in Cape Town ...
