I noticed on mine last night when I went to the grocery store, it was about 95 degrees out, and yes.. it was sorta cool coming out of vents......but not like it usually is.
But on Friday and Saturday morning it was fridgid cool coming out of it... the only thing I did was change the oil and replace the positive battery post terminal on Saturday morning, drive to post office, and grab a sandwich.
Nothing that I can think of that would affect the A/C system...
But I am going to AutoZone shortly to get a recharge kit...and check the level...