This glitch occurs when you switch the app's temperature unit from F° to C° on the Weather app, using iOS 6. This is a real pain for me, because I don't use Celsius.
So, I pressed hourly, and as you can see, it glitched on me. Yes, I did switch it back to F°.
To remedy this, press the little "i" in the bottom right corner of the previous screen, then delete the city that has the glitch. No, this is not a glitch, just photo editing.
Now, add the deleted city back to the list.
Everything is back in F° measurements. Thank goodness. In case you were wondering how I got the degrees sign, just hold down the number 0, until the option for ° appears.