You are overthinking it my man. Yes, the pressure does go up, but overinflated tires need to be way way way over inflated to explode. Unless you are a pro cyclist or store your bike in the trunk of your Kar in the Sahara desert... no, they don't pressurize enough to matter.

/not an expert

Yes, they can gain or lose pressure as the weather changes.

That said, as long as they've been filled within their specs, they're relatively unlikely to explode even with significant swings if they're just sitting there.

That said, it's still a good idea to check your pressure at the start of every day before you ride and adjust accordingly: Too much or too little pressure can cause all sorts of problems from pinch flats to premature wear to blow outs.

Pressure, volume and temperature are all interrelated.

Assuming constant volume; as temperature goes up, so does pressure to compensate. (Alternatively volume can also increase. While tire generally don’t expand much, they do expand slightly, since rubber is… well, rubber.)

Another person listed a good graph but yeah, the amount of volume change in air by temperature (assuming normal ‘human life’ ranges) are a matter of just a few percentage points. Any increase in air pressure is undoubtedly nullified by ambient leaks of air and similar in your tires.

We have a couple of bikes in our garage. In Australian summers it gets to a minimum of 50°c in there. No explosions to date.

Considering that you need to check tire pressures every 6-12 weeks, I wouldn't worry about the summer/winter difference.

On my bike the recommended pressure is in the 4-6 bar range. so way more than the expected variation from temperature (or day to day pressure).

It's not a bad idea to deflate them if you go through sudden temperature changes but it's important to remember that tires are porous and will slowly leak air over time so it's less of an issue in that direction... you also don't hear about it as much because people tend to bike more in warm weather so it's more likely for you to go long stretches of time without biking when it's getting colder.

So there are quite a few reasons why the deflation problem gets talked about more.

In short, keep the pressure constant, because 8bar will be 8bar in winter and in summer. It's kind of a 1kg of steel vs 1kg of feather type of deal. It's still 1kg.

But if you want the details, yes pressure will increase with temperature, they are directly related. Charles's law state "The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system." Since in bike tires volume is constant, it's given that pressure is the one to change.

And yes, tires do explode. I had mine explode when bike was left on the sun but it had underlying issue. Under normal circumstances they are usually engineered to withstand normally expected temperatures. Also tires get hotter when they are ridden and they also experience sudden raise in pressure when running over pot holes and similar.

Look up the ideal gas law.

But even then your tires won't explode due to temperature induced pressure change, unless you're about to blow them up already when cold.

Something I thought about recently as well. I might be wrong, but is pressure not just a differential from inside to the outside? If it gets warm, air expands inside the tire, but so does the air outside, pushing back. It kinda sounds right, but I don't know.