Extreme heat leads to more fatalities per year across america than any other weather event. When heat indices are between 105 and 120, the body begins to shut down because it can't cool off by itself.
This is when heat exhaustion or heat stroke can set in. Just remember if you feel the ache take a break.
The hottest Austin temperature ever of 112º happened on August 28, 2011 and September 2000. Four of the top six years with 100 degree days have been recorded since 2000.
In 2011, we experienced a record streak of 27 straight days in the 100s.
High pressure is the culprit of these heatwaves. This happens because with the northern hemisphere is tilted more toward the sun during the summer. The storm track migrates North leaving behind the dome of tranquil weather. The bubble overhead keeps the rain away and the sinking air compresses and dries out the air allowing the heat to thrive.
The drier the conditions the stronger the bubble of high pressure reach in turn will lead to a very hot summer.
Usually we get a dozen 100 degree days, but since 2000 we have gone through some strong droughts pushing the average number of days in 100s to 32. The summers are getting hotter not only because of higher frequency of droughts but also the urban development. This is leading to less vegetation and more concrete. The combination helps to radiate the heat and making the heat bubble stronger in recent years.