I'm surprised your TPMS monitors the temperature and has an alarm for that. The two that I have monitor PRESSURE, and show the temp as well. The alarms go off on high or low pressure. With my pressure set to 42 cold, I've seen 51 psi while riding on a hot day on the rear wheel. Since the temp is in a smaller, hard to read font, I don't pay a whole lot of attention to that, but it is easily 10 deg above ambient temp on hot days. I'm only monitoring the rear, not having changed the front since I bought the system.
Didn't the instructions have suggestions for set points? As I always say, when all else fails, read the instructions.