The temperature in a desert rose $1.5$ degrees in $15$ minutes.  If this rate of increase remains constant, how many degrees will the temperature rise in the next $2$ hours?
Firstly, we find that the temperature rises $\frac{1.5}{15}=0.1$ degrees per minute.  Thus, since $2$ hours contains $120$ minutes, we find that the temperature will rise $0.1 \times 120=\boxed{12}$ degrees.