If you have never been to Texas, be warned: the weather can be random. Anyone will tell you this. It can be 15 degrees in the morning (only during some winter months) and rise to 60 degrees by 2 p.m.
Be well prepared for all seasons when you come to these parts. However, don't forget your swimsuit. You surely will want to bring that since, well, this is Texas, and there is the San Marcos River, running crystal-clear water right through campus at a consistent temperature of 72 to 74 degrees year-round.