The keyboards used in Germany and Switzerland have the degrees symbol already on the keyboard, but us stuck with the QWERTY board have to result to drastic measures whenever we want to type °.
Some people just type out "degrees," but this is just for people who give up to quickly.
I used to just do a google search for "degrees," then went to the Wikipedia page, copied, then pasted the symbol in.
But I finally just looked up the quick code. This is how you do it:
Hold down "Alt" then type "2" then "4" then "8" then let go of "Alt."
In other words: Alt+248
°
BAM. There you go. So easy.
(Just remember that if you're giving the temperature in Kelvin, don't use the degree symbol. It's only used for Celsius and Fahrenheit. Or Rankine. Or if you want to measure the angles of arc.)