#### Answer

Increasing from 6 a.m. to noon and from 2 a.m. to 6 a.m.
Decreasing from noon to 2 a.m.

#### Work Step by Step

Using the graph we notice the intervals on which the function is increasing/decreasing:
-The temperature was increasing from $x=0$ to $x=6$ (from 6 a.m. to noon).
- The temperature was decreasing from $x=6$ to $x=20$ (from noon to 2 a.m.).
- The temperature was increasing from $x=20$ to $x=24$ (from 2 a.m. to 6 a.m.).