On the contrary. Tires should be kept at the recommended pressure at ambient temperature. You should not check your tires when they are hot (immediately after driving), but other than that the surrounding temperature is irrelevant. Do you think tire manufacturers only inflate tires at one specific temperature?
Let's not turn this into Neowin and argue against obvious facts, shall we? Correct tire pressure should be maintained by the user and checked regularly when outside temperature varies (and even when it doesn't, for that matter).
No no- see, when they define the standard tire pressure for the tire, they aren't saying "X PSI for <all temperatures> but are rather defining what the tire pressure should be at a industry standard temperature; this is, in fact, the way many other things work. Basically, what I'm saying is that a leading cause of such issues is that the tire is originally inflated, in, say hot conditions, say 40(c), to- say, 28PSI, which is shown on the sidewall. Great- that's where it's supposed to be.
Except that when the temp drops in winter to -20, the tire pressure drops to maybe 25 PSI. (probably more) basically, what I mean is inflating it to the "proper" PSI in a non-standard temperature environment will exacerbate the pressure change when the temperature fluctuates. OF course, if you check it regularly, you'll be fine, and in the case of a cold-air inflate to a hot air inflate you'll probably be even better off, since the estimated 1psi per month loss will probably compensate for any perceived gain from the temperature increase.
Not that it really matters, you still should check it anyway and make sure the tire pressure is proper, no need to try using long complicated formulae to determine tire pressure when you can just check the *censored* thing as you've said.
Basically, what I'm saying is, that if the tire was filled to the appropriate PSI at the standard temperature (I'm not sure what that is, but any pressure-based metric has one) then the tires will be usable at most temperatures. they should be topped up, though. The issues arise when you fill the tire at a non-standard temperature and then the temperature flip-flops, it's far more likely you'll exit the manufacturers "safe, but you should *censored* well fill up your tire" pressure.
Since temperature is not the only variable anyway (air leeches out on it's own and so forth) it is of course imperative to check the pressure. And I wouldn't be caught dead trying to calculate what I need to fill my tire up to in -10 degree weather to equal the pressure at 21 degrees, because the optimal pressure at any temperature is still the one stated on the sidewall. My main point is that the manufacturer's "safe for driving" borders center around the recommended PSI only for the standard temperature. (which won't matter anyway since your supposed to be checking your tires anyway.)
