Why does 15 degrees (59 farenheit) feel so much colder in the night, than it does during the day?

469 views
0

Why does 15 degrees (59 farenheit) feel so much colder in the night, than it does during the day?

In: Physics

>Why does 15 degrees (59 farenheit) feel so much colder in the night, than it does during the day?

Humidity of the air greatly affects perception of temperature with your skin. Water vapor floating in the air transfers temperature quicker. Sun reduces this humidity with direct light, but at night it goes back up.

Because you don’t have sunlight warming everything. When the light hits surfaces and structures, those things absorb some thermal energy and heat up. So even if the air temp is only 15 deg. C, your body, the ground, or a building or vehicle that you’re in will be noticeably warmer because they’ve been absorbing the heat from sunlight. At night, without anymore sunlight to generate heat, all of those things shed the excess heat and come down closer to the air temp.

The temperature you feel, is due to heat transfer to and from your internal “thermostat”. Temperature is just one element of that heat transfer. At night, you don’t get the heat transfer from the “radiation” of the sun. Even though you get roughly the same “conduction” and “convection”(the 3 modes of heat transfer are radiation, conduction, and convection), you don’t feel the heat coming from sun on your body.

It’s basically the same reason that 70 degrees in water can make you go hypothermic, but 70 degrees on a still day in the sunlight is entirely pleasant, or the reason in the morning carpets feel fine to your bare feet but tile is too cold.