Does "sea level temperature" exist? When reporting barometric pressure, weather stations normalize the 
result to sea level using a well-known formula (approximately, add 1 
inch to the measured pressure for every 1000 feet above sea level, but 
I believe the formula they use is more precise). 
Does a similar concept exist for temperature? As altitude increases, 
temperature normally decreases. Is there a way to compensate for this 
effect? 
Reason: I often notice "unusually cold" spots on temperature maps, 
which are usually the result of high-altitude stations. It'd be nice 
to see what the temperature would look like if all stations were at 
sea level. 
 A: Meteorolists have something they call potential temperature, the temperature a parcel of air would acquire if it were adiabatically changed to another pressure. An adiabatic process means only the pressure (and volume) is changed, but ho heat is added or subtracted. Water vapor must be taken into account, as phase changes (condensation or evaporation) effect the heat capacity. A potential temperature at standard sea level pressure (1013 millibars) is what you are looking for.
A: What you're asking about is lapse rate.
Aviators use a rule of thumb that temperature falls by 5.4F (3C) per 1000' altitude.
At the same time, dew point also falls by 1F (.55C) per 1000',
so the the temperature-dew-point spread falls by 4.4F (2.4C) per 1000', which allows estimation of where the bottoms of clouds will be.
In actuality, temperature as a function of altitude varies greatly with the weather conditions, resulting in instability (colder than it should be at elevation) or inversion (warmer than it should be at elevation).
