Hooked up a Scan Gauge II this spring to monitor trans temp among other things. On average, my trans temp runs about 90 - 100 degrees above the incoming air temp during the day. This is based on 1k miles in May between east TN and the Florida panhandle, 900 miles in July from east TN and Hilton Head Island and 4.5k miles between east TN and southern UT between late August and late Oct.
2005 Allegro Bay 34XB, W22 Chassis / 8.1L
2013 Honda Fit toad, Demco Dominator & base plate
RVi2 Brake System