2011 WRX engine temps?

Noticed my engine water temp gauge was a little higher than normal on a trip this weekend. About an hour drive down the freeway each way and I noticed the water temp was getting up to the mark right above the middle one after about 45 mins of driving. We had the AC on and the temp went back to normal after I turned it off. It was also getting near 100° outside today. How abnormal is this and should I be concerned? I plan to check coolant levels after it cools down