I must say I am really suprised how many people in the U.S. believe global warming does not exist - it is actually quite rare here for someone to think that. Yes I see often people do not believe that it is caused by humans, but the scientific evidence for global warming as such (whatever the reason may be) is very strong.
In this particular case for example I could say that:
1) what makes you believe that it just happens to be that the stations are in places that are warmer (even if they were not correctly sited, why do you think there would be a bias towards placing them where it is warmer, they could just as well be poorly sited and so be cooler than they should)
2) more importantly though, what about remote sensing.... that disproves your theory, satellites are quite accurate and can measure the temperature quite accurately. Not with such high resolution, but we are not interested in the weather in the town XY, but globally.
Of course it could be just anomaly, probability issue that a certain month is the hottest, but if it is 14 months in a row.... yes it can still be just "luck", but the probability is so low that it is hard for me to believe it, not to mention the many other evidences.
But as you said, I am not going to try to persuade you, the problem is that if someone wants to believe something, they will always find a reason why your arguments are questionable, just like many still believe we never landed on Moon, evolution did not take place or even that the Earth is flat and whenever you prove that their argumentation is flawed, they come up with different one.