4l60E Transmission Temperture?

Usually about 70 cooler than the engine, unless its around 100 degrees outside. Then it's closer to 50 degrees below
 
hottest i can get mine to run is 140 with a converter,if its cold,trans temp wont even come off 100degrees on cluster,and its accurate,ive checked it with multiple scan tools
 
Hottest I have ever seen mine get was around 190. It usually ran about 170-180 in the summer time though, and about 150-160 in the winter.