Mailbox Sensor High Temperature False Alarms

The weather here in Cincinnati is in the 90's the last few days and our mailbox sensor has been giving false alarms. I called a friend who also has a mailbox sensor and he's had a few false alarms as well. Is this a problem that others are having?Our mailbox is black and I would imagine the temperature is quite high and certainly much higher than the ambient temperature which has topped 95 or so over the last few days.