On my 2004 w/ Hemi I have never seen the temp gauge go over 1/2 way. Actually it never quite makes it to halfway and I have been in 105 degree heat w/ ac on and stopped in traffic.
I don't drive mine very often, it is the wifes car but it has a standard clutch fan on it and I know I have also heard an electric fan when I am sitting still, maybe your electric fan quit?
+2 on checking the electric helper fan . Sounds like yours is not working. Should run continously when A/C is on, and also I think if engine temp is over 210.
Don
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2001 Dark Garnet Pearl Durango SLT+ 4.7L
AWD w/ 3.55 gears (mine)
2005 Linen Gold Pearl DGC 3.8L (hers)