Temperatures
Tenerife has the most balanced climate in the world. You won't find any other place in the planet with such a lack of temperature variations. In winter, the temperatures keep around 20 degrees and in summer time they don't get higher than 30. To find out  what's the temperature at this moment just take a look at the graphic. The annual temperature in Tenerife is always higher than in the rest of Europe during winter time, and that's because of the sun rays, which are more intensive and let let you enjoy beach holidays in Tenerife during winter time.

The sun
The sun in Tenerife is one of the most important reasons of why 5 million people visit the isle. It's shown in the graphic and it can be compared with the rest of Europe during winter time. You should not forget the sun protection lotion at home. The power of the UV rays at the end of december is 5. This value power is reached in countries such as Germany just during the sunny spring days. In february, these UV values are the same as in these countries during summer time.