I checked mine last week on the way up to Orlando on the 5th wheel. All 4 trailer wheel hubs were in the 120°F range, plus or minus 3°F. My front truck hubs, after pulling into the rest area on the turnpike, were both in the 145°F range, probably from using the brakes on the truck to get off the 4 lane. Outside air temp was in the mid 80s and I was running about 62 mph for about an hour the first time I checked them. Then checked them again after about another hour and they were holding the same temperature as the first check.
