the air temp should never be that hot. 80 is fine. air temp of 90 means the hot spot is WAY to hot.
Sounds like your set up just needs to even out.
To give you an example, i have my heat tape set to 96. The enclosures hot spots are between 90-94 depending on what level they're in on the rack. The ambients (air temps) hover around 80-82.