The question of how hot it has to be outside to get a tan is an interesting one. The truth is that the air temperature has absolutely no effect on whether a person's skin tans. In fact, it's possible to get a tan even if the air temperature is extremely cold. People in cold climates can get a tan, or even a sunburn, when the air temperature is below the freezing point of water. The only heat that really matters in the tanning process is the heat from the sun.
How Does Tanning Occur?
Tanning does not occur because of high temperatures outside, as some people believe. This common misconception comes from the fact that it is usually warm outside when conditions are optimal to go tanning. Why? It is sunlight that tan's a person's skin and strong sunlight also warms the Earth's surface, creating higher outside temperatures. As sunlight hits a person's skin, the ultraviolet radiation contained in the sunlight causes a two-pronged effect. First, the melanin (dark pigment) that is already present in the skin darkens. Also, the skin creates more melanin in reaction to the exposure to ultraviolet radiation.
What Else Should I Know About Tanning?
The reason that the skin darkens and creates more melanin when it is exposed to ultraviolet radiation is that such radiation is extremely bad for the skin. Ultraviolet radiation, left unchecked, causes damage to the skin at a molecular level, creating an ageing effect. It can also cause cancerous growths, some of which can be fatal if left unchecked. It is important to remember, then, that tanning is actually a very slight form of burning to the skin. Doing it too much can lead to disastrous effects, even to death.