Tgf - do not get confused between the corrections you (ATC) have to make and those which pilots have to make.
Yes, we have to correct for non-standard OAT, but we correct
via the QNH which the aerodrome has provided as said above. We do
our bits and you do
yours and we both let each other get on with it!
If you are interested in 'our' corrections, we get enumerable posts (from people who do not 'search' first
) popping up about the corrections and they usually all flower in autumn/winter. Search for 'altimeter' or 'temperature correction' or 'cold weather' or similar and ye will find.
Edited to correct misunderstanding!