With the end of August, meteorological summer is over in Austin. While the National Weather Service is still processing some data, it is safe to say that this was the hottest summer in the city’s recorded history by most every measure but one.
Let's start by looking at that exception.
Camp Mabry is Austin’s official weather station. We have the longest consistent years of temperature records there and it best reflects the weather conditions in much of Central Austin.
Earlier this month it looked like the average temperature for June through August at Camp Mabry was primed to break the record set in 2011, Austin’s hottest year ever. In the end, the average temperature at Mabry fell just short of setting a new record.
The average temperature this summer at Mabry was 89.4. The average temperature in 2011 was 89.5.
“Yeah, it was definitely a photo finish,” National Weather Service meteorologist Emily Heller says.
But, Heller says, most other weather stations in the area did record their hottest summer yet, including the station at Austin-Bergstrom International Airport, which typically runs a bit cooler than Camp Mabry.
“For Bergstrom, we are the hottest with the mean average temperature of 87.1. The second hottest was in 1954 with 86.7. Then 2011 falls to number three [hottest],” she says.
Austin records longest streak of triple-digit days
But, more than average temperature, it was the extreme heat that made this summer so different.
At Camp Mabry, Austin recorded 45 days straight of hitting triple-digit temperatures, the longest streak in the city’s history by a longshot. After one day hitting just 99, we returned to triple-digit highs for another six days straight.
This year’s triple digits were also consistently far hotter than anything previously recorded. Forty of them topped off at 105 degrees or hotter. That’s unlike anything the city has ever seen.
The whole experience was more surprising because the month of June actually started out relatively cool. Austin had to play catch up with previous years to get into the running for hottest summer by average temperature. But day after day of excruciating heat did just that.
By the end of Friday, Austin will have clocked its 70th triple-digit day of the year. The record number of triple-digit days in a year is 90, set in 2011.
Above average temperatures stick around
While August is behind us, the heat is not.
Austin remains locked in a heat and drought climate feedback loop that’s expected to keep temperatures above average for the foreseeable future. These types of heat waves are only expected to worsen as fossil fuel emissions continue to warm the atmosphere.
Looking for some good news? There is one thing that is already keeping the city somewhat cooler than it might otherwise be: shorter days.
The National Weather Service points out, by this time of year, we lose about one minute and 45 seconds of sunlight a day. That means less solar energy to heat us up, and longer stretches of darkness to cool us off at night.
Heller says those longer nights might be one reason our mornings are feeling a bit cooler lately.
Even though the morning temperatures are still a degree or two above the historical average, “it's relatively cooler from what we have seen,” she says.
