Austin has a subtropical climate. May - Sept can be very hot with high temperatures over 90 and often close to 100 degrees. Winter temperatures vary with highs often near 60 degrees and lows in the 30s or 40s.   Snow isn't likely, but ice storms can come in from the north, usually in January.  Spring brings thunderstorms, but really nice temperatures.  April and October tend to be the best times to visit in terms of weather.