Ten years ago: Austin’s hottest summer wraps up

(KXAN File Photo)

Posted: Sep 14, 2021 / 02:30 PM CDT

Updated: Sep 14, 2021 / 02:45 PM CDT

If you’ve spent any time in Central Texas, you know the weather can change drastically within a day’s time. But back in 2011, the slow onset of what ended up being the hottest summer ever — as well as one of the driest years on record — caught many by surprise and led to billions in agricultural losses, a water shortage and the worst wildfire in Texas history.

The start of this slow-moving disaster began in October 2010 as a strong La Niña began. October is the second wettest month of the year, with an average rainfall of 3.91″. In 2010, however, Austin Camp Mabry only picked up 0.08″.

The below average rainfall continued through the winter and into spring 2011 when typically wet months like March — which averages 2.88″ — and April — which averages 2.42″ — only picked up 0.09″ and 0.27″, respectively. At this point, much of the state was in some level of drought.

Austin’s average rainfall between October and May is 24.42″. During the eight-month stretch from October 2010 to May 2011, Austin only recorded a third of that – a little under 9 inches. Dry soils exacerbate drought because there’s no moisture to evaporate and moderate temperatures.

The first 100 degree day was recorded on May 25th, 2011. By the end of the month, there would be two more triple-digit days, for a total of three 100 degree days during May 2011.

By June, we saw a 10-day stretch of 100 degree days before a 1.99″ rainfall that occurred on June 22, 2011. The soil moisture from that rain event helped keep temperatures down for about a week, before the next 100 degree day occurred on June 30.

July was when conditions deteriorated drastically. Of the 31 days in July, only two days were below 100 degrees, and it wasn’t by much – only 99 degrees for both days. Only 0.05″ of rain was recorded as well.

Austin entered August on a 15-day stretch of 100 degree days that continued for another 12 days until a high of 97 was recorded on Aug. 13, 2011. Similar to July, only two of the 31 days in August were spent below 100 degrees, with one 97 degree day and one 94 degree day. Only a trace of rain was reported during the entire month.

By the time we reached September, we had hit 100 degrees or hotter for 76 days, but would still add 14 more 100 degree days before the streak came to an end on Sept. 29.

As summer 2011 came to an end, the drought alone accounted for billions in losses for farmers and ranchers across the state. In the peak of the drought, 81% of the state of Texas was experiencing “Exceptional Drought” conditions – the worst category drought there is, according to the U.S. Drought Monitor.

Drought conditions for the week of September 6, 2011
Courtesy of US Drought Monitor

Brought on by the drought was a water shortage that lowered Central Texas lakes to their lowest levels since the 1960s. Lake Travis reached its third lowest level on record of 626.38 feet — surpassed only by the drought of 1963-64 that recorded a level of 615.02 feet, and the lowest of all time during the drought of the early 1950s, when it was at 614.18 feet.

Then, there was the Bastrop Wildfire. By the beginning of September, the entire state of Texas was a tinderbox and all it needed was a spark. That spark came in the form of high winds from nearby Tropical Storm Lee that caused tree limbs to fall onto powerlines, igniting the worst wildfire in Texas history.

While a streak of triple-digit days came to an end in September 2011, Central Texas did not get any relief from the drought until January 2012, when nearly every month of that year saw above average rainfall.

However, it still took the lakes years to recover. It wasn’t until two major flood events in 2015, on Memorial Day and Halloween, to bring the lakes back to above normal levels. However, this came with the price of two catastrophic flood events within one year.

The following are the records that were broken following the summer of 2011: