Sun protection tips for autumn and winter are more important than you think

The main reason why many people ignore sun protection in autumn and winter is that the sunlight is not strong. In fact, ultraviolet rays have little to do with the intensity of sunlight, and they will not be weakened too much due to the weakening of light. It’s just that the clouds are thicker in autumn and winter, which can block more ultraviolet rays, but the effect is not ideal. Ultraviolet rays are everywhere all year round.

Do you still need sun protection in autumn and winter?

It is recommended to check the UV index directly to determine whether to use sunscreen.

Although there are regular patterns in the changes in ultraviolet intensity, my country is a vast country after all. Unlike some countries where the weather forecast can be solved with just a simple statement "It will be cloudy across the country tomorrow", so it is recommended to use the pattern as a reference.

▍Sunscreen is required when the UV index is ≥3

The simplest way to judge is to look at the UV Index, which is also the method recommended by WHO.

When the UV Index is ≥3, it is recommended to take sun protection measures.

Some apps or weather websites don't have specific values, but recommend taking sun protection measures when UV intensity is moderate or above.

In other words, when the UV index is <3 or the level of ultraviolet radiation is low, you can play outside without worrying about applying sunscreen.

▍Low temperature does not mean you don’t need sun protection

The coldest time of the year is also when the UV intensity is relatively low on average.

But this minimum is also relative and is different in different regions.

It is still the most reliable to directly look at the ultraviolet intensity.

Even so, there are still rules, otherwise I wouldn't say without hesitation that I didn't wear sunscreen.

▍The overall intensity of ultraviolet rays is low in autumn and winter

The tropical areas close to the equator have very high ultraviolet rays all year round. For example, in Bali, where we went for team building in July, it is really necessary to protect yourself from the sun all year round.

But our country is located in the mid-latitude region, and the intensity of ultraviolet rays in summer and winter is quite different.

Take Beijing as an example, the difference between different seasons is probably like this:

Most parts of our country follow this trend, but the difference between the highest and lowest levels becomes smaller the further south you go.

Of course, this data is slightly different from my own observations and feels a little lower, but the general rule is correct.

According to the above-mentioned requirement of taking sun protection measures when UV≥3, you don’t need to take special sun protection measures in Beijing in October unless it is a sunny day, especially for those who do not spend much time outside every day.

▍UV intensity is lower in the north

This is easy to understand. The higher the latitude, the greater the angle of the sun's radiation. This will not only affect the temperature, but also the intensity of ultraviolet rays.

So on average, the more northerly the area is, the lower the UV intensity will be in winter, and the further south and closer to the equator you go, the smaller the drop in UV intensity will be compared to summer.

▍These rules are not so absolute

These rules are only generally applicable, but when it comes to a specific day or place, they are still affected by many factors and cannot be generalized.

For example, according to the rules, the intensity of ultraviolet rays should be Haikou > Shenzhen > Shanghai > Beijing, but when I actually checked the weather forecast, I found that they were not the same.

It can be seen that on the same day and with similar weather conditions, the UV intensity in Shanghai is lower than that in Beijing, and in Haikou is lower than that in Shenzhen.

Of course, this does not mean that the law of different ultraviolet intensity at different latitudes is wrong, but when it comes to a specific day, we still have to deal with practical problems practically.

Therefore, the best way to judge is to check the intensity of ultraviolet rays.