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When air gets colder, the air molecules get closer together. Does this mean that for a given wind speed, the wind will push much harder against objects and people at a lower temperature than at a higher temperature?

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    $\begingroup$ Ask a sailor 'does a sail boat go faster in colder or warmer weather'...... $\endgroup$ – mattnz Mar 29 '17 at 9:26
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Colder air is more dense, so an airplane needs less absolute airspeed, and therefore less runway, to take off in it. Check my favorite e-book about aviation.

Absolute airspeed is not the same at indicated airspeed, which is what the airspeed instrument shows. It works off of a pitot tube and static port. These together measure the pressure difference between a hole pointing forward and one pointing sideways. That's a good thing, because what wings care about is the actual air density. They don't care about meters per second.

Pilots have to consider the density of the air. At higher temperature it is thinner. At higher humidity it is thinner. At higher altitude it is thinner. Also, when air is thinner, the engine generates less power, unless it is turbocharged. All those things mean taking off requires more runway, as does carrying more weight. So pilots have acronyms and memorized sayings. One of them is "beware of HHH" - high, hot, and heavy.

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