Surface temperatures of tires on a heavy fiver can easily reach 130-140 or more on a relatively warm day. I use the infrared EVERY stop and this is always 10-20 degrees hotter than the TPMS reads. As was stated, you are looking for the delta between the 2, 4 or 6 tires. If 3 read around 125 degrees and 1 at 145, it is time to stop and find the reason. Remember, TPMS will only give you the approximate temperature of the rim, not the surface of the tire. A combination of watching all three, pressure, surface temp and TPMS temp will usually keep you between the ditches.
Jim in Memphis, Wife of 51 years is Brenda
2019 F450 6.7 Powerstroke
2018 Mobile Suites 40RSSA
2021 40' Jayco Eagle
2001 Road king w/matching Harley sidecar
2021 Yamaha X2 Wolverine 1000