Do Wi fi Signals Travel better when it is really cold?

Question

I notice a change when it gets cold.

Answer 1

No. Especially not indoors. Whether it is a cold day in winter or a hot day in summer, the signals at 2.4GHz and 5GHz don't travel any "better" in one condition or the other to any significant or even measurable degree. Consider it a coincidence.

What the other answer is referring to is, for example, suppose you have a long distance wireless bridge link, one end up on a mountain and the other down in a valley. Cold air up on the mountain and warm, humid air down in the valley. This air stratification causes RF signals to refract (bend) such that the RF line of sight is different from the visual line of sight. This is not a concern with standard wireless access points with omnidirectional antennas and much shorter distances than a wireless bridge link.

Likewise, wind has no effect on RF signals and neither do rain or fog or snow unless it's very heavy rain or fog or snow. Or if there's several inches of snow on a rooftop for exmaple. Smog on the other hand contains chemicals that can cause the RF signal to refract. Again, this is more of a concern for long distance outdoor links.

So is there something else that's happening in the warm versus cold weather that might cause this coincidence? Like having windows open versus closed? Tinted windows use aluminized mylar and reflect RF signals for example. Maybe you run an electric heater when it's cold in the vicinity of the access point, that would create a small but significant temp difference (like the air stratification above) that could cause some refraction.

There's got to be something else causing it, not just the cold. I suggest walking around with a laptop and doing a site survey.

Answer 2

Technically yes, colder temperatures provides for less reflection, and refraction in the air.

If you would like to look in to this phenomenom further there is alot of this type of study regarding sattellite communications.