The weather in Austin is unpredictable. You can have just about any kind of weather that you could want in Austin. It rains, it snows (every once in awhile). It's hot, it's cold, it's warm, it's cool, it's sunny and it's cloudy. And we average 300 days of sunshine a year. Could you ask for much more? We have summer/springtime weather nine months out of the year, fall for two months and one month of winter. It hardly ever gets really cold, and the winters are generally mild. It did snow in 2003, though, and that was fun for everyone-we even got a snow day off from school. However, this is definitely a rare occurrence. The summers are hot, with lots of days in the high 90s and 100s.
As for clothes, bring jeans and T-shirts, shorts and tank tops, sweatshirts and one jacket, but nothing too heavy because you will not need it. Oh, and don't forget your umbrella. It rains fairly often here, but it then clears up pretty clearly. A popular saying in Texas is "If you don't like the weather, wait 10 minutes." That saying definitely applies in Austin. Overall, the weather is great; just don't get too attached to any certain kind of weather, because it will change for sure.