1997 Holden Vectra V6 Engine Running Hot With A/C On.?

I've only had my Vectra for 3 weeks, and thus far love it, today was the first time I put on the a/c. I've noticed that the engine sits at around the 90 degree mark on my temp gauge normally. When I popped the a/c on it quickly started rising toward the 100 degree mark, I was just wondering if this is normal? Coolant level is normal and the thermo fan seems to work at least at start up and shutdown of the car. The outside temp was 30 degrees based on the trip computer or 28 degrees based on the radio news. I was also driving in an urban area (Narellan NSW) with smooth flowing traffic, but needing to stop at red lights.