All of the following are true about Saudi Arabia EXCEPT:

The statement regarding the average temperature in December being 50°F is inaccurate for Saudi Arabia. During December, temperatures in many regions of the country can be significantly lower than that, especially at night. In some areas, particularly in the northern regions, it can drop below that temperature, while in more southern or desert areas, it tends to be much warmer.

In contrast, Saudi Arabia indeed has a predominantly young population, making up a substantial portion of its demographic. It is recognized as the largest country in the Middle East, covering an area that exceeds that of any other country in the region. Additionally, Saudi Arabia is home to the Two Holy Mosques in Mecca and Medina, making it a central location for Muslim pilgrimages. This context helps to understand the significance and geographical features of the kingdom, thus demonstrating that the other statements hold true while the temperature aspect is inaccurate.