I don't remember the official answer, but there is a cerrtainn ambient tempurature where, per the POH, you are not supposed to operate the aircraft.
None the less, you are going to be having some fun. I did the bulk of my PPL training in a DA20 and throughly enjoyed it. The center stick is makes contorl a bit more natural than a yoke. The handling is very light and sporty. And even on a hot day, the DA20 and its smaller engine climbs like a express elevator with SRB's attached. And be right on the correct approach speeds on final, else that glider wing will float you for a long way. Oh, and did I mention the excellent view?