Arent we off the OP topic 8-12 knots now (again)?
But IMO temperature is quite easy to feel as a difference powerwise.
Humidity means nothing whatsoever, as only 1-2 % difference from 0 % to 99.9 % relative humidity in terms of density (and the dry air gives you the most power as the atomic weight is higher)
Whereas going from 0° til 30° air means around 10 % difference in density (lift).
BUT, as most of us ride where the temperature slowly increases or decreases, we will not notice this difference in reality.
Only if you travel between two opposites, you might feel this difference very distinct.
Around here, and I believe in most countries with frontal systems, we usually have more gusty wind in the wintertime, so not only is the density higher so the wind hits "harder" - but when combined with winter gusts it feels even more different than soft smooth gutless summerwind
Which can trick us a lot, so we conclude based on the wrong facts.
But the warmer the air, and the more moisture - the less power you get with a given kitesize.
Humidity can not be felt as less than 1 % difference around 20° and only 1.5 % at 30°.
Peter
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