Turned AC on and temp spiked within 4 minutes!

Driving down the interstate and a 80 degree day so I flipped the AC on. AC is putting out cool air and then a couple minutes later my check gauges light comes on and my Temp is near 240 degrees. I flip the AC off and the temp drops fairly rapidly back to normal 210-215 degrees. The AC compressor does make a small chirping noise when clutch engages. Let me here your best guesses as to why this would happen all of a sudden when I didn't see anything more than 5-10 degree increase last year?

Does your electric fan turn on? What's the air temp at the center outlet?

Yes, electric fan does turn on. I didn't get a chance to put a thermometer in the vent.

Had a similar problem once, driving around town, temps were getting a bit higher than I would prefer with the A/C on. (Not quite 240, but definitely over the half-way mark.) Replacing the fan clutch fixed it, although I probably could have just cleaned the grease and crap out of the bi-metallic strip on the old one and been fine.

Speaking of fans and such, how's the shroud look? Good and complete or busted/missing? Any other cooling stuff we should know about? (Different fan, radiator, cap, thermostat or lack thereof, water pump, etc.)

so you where driving at speeds over ~50mph and it started to creep up? i would check for debris stuck in the radiator and condenser. how old is the cooling system parts?

Yes driving at 65mph and it didn't creep up it went up in a hurry. New water pump, thermostat. Not sure of condenser and radiator, they could be originals. Its just strange it happened so quickly.
I did just add a bull bar to bumper and I have noticed a rise of about 7 degrees since then during normal driving. I will do more diagnosing tonight.