Checking tyre pressures when when parked on a hill

[Pine]

In the car park outside my flat I very frequently have to park across a slope so that the drivers side is slightly lower than the passengers side.  I try to remember to check my tyre pressures once a month and whilst doing so I often wonder if the tyre pressures are affected by the way I am parked.  Is more weight being transferred to the tyres on the lower side and does it affect the tyre pressures?

[Lord Voltermore]

Yes it could transfer more weight  to one side, compressing the tyre wall, so the same quantity of air is squeezed into a larger (or smaller) tyre volume .This volume will change/equalise when the car is moved. 

On a slight slope the difference may not be enough to worry about . You could  take the cold pressure  parked one way then turn the car around to reverse the slope affect  and measure it again. Then you will know for sure. 

The same problem can occur if one side of the car is in the sun and the other in the shade .  (Cold air is denser and expands when the tyre warms up. )I suspect a temperature difference between sides might sometimes affect tyre pressure more than a slight slope.