Austin and the surrounding Hill Country enjoy some of the most temperate weather in Texas. Summers are hot, winters are mild and spring and fall months are typically quite pleasant. Sun shines in the Austin area for 300 days or more and 90 degree plus temperatures occur on about 110 days out of the year. That means 200 sunny days in Texas are less than 90 degrees Fahrenheit, more if you consider the fact that there are overcast days in the summer that can be very hot.

So why the oft-repeated truism about the sudden changes in climate? That's because of the nature of some of the more severe weather events that can affect the area. Flash floods are the most common and deadly type of weather-related disaster in Austin proper. Of course, the very name indicates the suddenness with which these kinds of floods strike. The storm systems that provide the massive amounts of rainfall that cause local rivers and creeks to flood can form suddenly as well, turning a hot, sunny afternoon into a wild, raging thunderstorm in a matter of minutes.

Most of the time, these storms merely provide excitement and welcome relief from summertime heat, although residents must take precautions against the threat of lightning strikes and rising streams at low water crossings. Occasionally however, massive super-storm systems, often the remnants of hurricanes that hit the Texas or Mexican coasts, will dump huge amounts of rain over short periods.

The greatest rainstorm in the continental United States occurred in 1921 when the towns of Taylor and Thrall, just northeast of Austin were hit with 23 inches and 36 inches of rain respectively in less than 24 hours. In all, seven Central Texas counties were severely affected and more than 200 people died. Over the years, severe flooding has occurred in the area about once every ten years on the average. Not only have many people been killed by these deadly floods, but damage to property and homes can climb into the millions of dollars. (Federal flood insurance is available in Austin through the city's participation in the National Flood Insurance Program.)

The fact that such dramatic flood events precede or occur after significant droughts also lends weight to the perception that Texas weather is rather fickle. A deadly flood in 1915 was followed just two years later by what was the driest year of record in many parts of Texas and the third driest in Austin's history. The great storm of 1957 that, according to the Austin American Statesman dumped "up to 10 inches of rain within a few minutes in a wide sweep of middle Texas.", struck at the end of a seven-year drought, one of the worst to ever hit the state.

One of Texas most deadly and unpredictable weather events, tornados, have only actually touched down rarely in Austin itself, although the surrounding countryside has been often hit with devastating results. The town of Jarrell to the north was virtually destroyed by an F-5 tornado on May 27, 1997. 27 people died in that storm. However, from 1953 until the spring of 2005, only 2 people died in tornados in Austin proper.

What about those mild winters? It rarely snows in Austin. The heaviest snow of record occurred in 1937 on November 11 when 9.7 inches fell. The last snowfall of significance occurred on Valentine's Day of 2004 and was completely melted by noon.

Freezing weather does hit the area most winters, although it doesn't usually last for long. In 1983, Austin set a record for the longest number of hours of sub-freezing weather, 140, from the 21st to the 27th of December. Although such cold temperatures rarely bring snow, they can cause freezing rain and sleet many winters.