We've had temp difference of 10 degrees, 25 miles away....You would need a , gazallion, bazillion points for every second of every day to compute some kind of world average. And the problem still remains in the historic averages...which are concocted from here and there when they felt like it.
Exactly. Most cars show outside temperature readings in them these days. Drive 10 miles and watch how many times that reading changes. These days, the “global average temperature” depends on what your politics are and how many grants you are getting.
Indeed. NOAA says that our temperature here is the same as at the airport in Akron. It is frequently off by 10° from our weather station.