How hot is the Sun?

The Sun is extremely hot! The center of the Sun is at least 10 million degrees. The “surface” of the Sun (what we see) is only 5800 degrees Kelvin (~10,000 Fahrenheit). This is cool for the Sun but is actually hot enough to melt any material found on Earth. 

The outer atmosphere of the Sun, the corona, which we don't normally see without special instruments, gets extremely hot again, about 1.5 to 2 million degrees. These huge temperature changes are very interesting to scientists.