The max is cold tire pressure not the pressure when the tire is hot.
Cold pressure is because that is the only reliable way to check. Because you dont know howmuch it has cooled down already , when you measure.
The cold advice is determined to give the tire warm a deflection that wont overheat any part of it,.
Cold advice is determined for 18 degr C/ 65 degr F., some say its 20/68 but not worth discussion because difference in pressure is marginal.
So cold is when inside tire temp is same as outside tire, so ambiënt temp.
So even when outside 100degrF it is called cold pressure when inside tire also 100 degr F.
Within a sertain range of ambiënt temp difference in pressure is marginal, but above 80 degr F , you should calculate te pressure back to that65 degrF.
And with TMPS with internal sensors, temp reading is pretty accurate, so nowadays you could measure warm pressure, and calculate back to 65 degr F. Some TMPS systems do that for you. Its yust a piece of software they have to make for that, using temp and pressure reading.
When 100 degrF cold measured, dont lower to advice, the tire needs that higher pressure to give lesser deflection, so lesser heatproduction a second , because cooling down is also les then , because of lesser temp diferences between rubber and in and outside air.
Reading back, I saw that I reacted on a topic from 2012. Dayly I google for pressure of last 24 hours, so wonder why this old topic came up.