Originally Posted by
DanK
I was puzzling over this as well. I was thinking that the presence of wind might slow condensation slightly by disrupting the formation of droplets, but that may have been farfetched. Basically, once a drop in temperature brings relative humidity up to 100%, water has to condense as the air chills further. Would wind matter much?
Clear skies per se have nothing to do with it. However, clear skies are generally a sign of relatively dry air, and dry air cools faster. It's an interesting question: dry air cools faster but has to cool more to reach the dew point, while humid air cools more slowly but doesn't have to cool as much. Which reaches the dew point faster?