Editor’s Note: This story was updated to reflect the official final numbers for 2023.

AUSTIN (KXAN) — For years, hot summers in Central Texas have been judged by comparison to 2011 — Austin’s hottest summer on record. But as meteorological summer ended at 11:59 p.m. Aug. 31, it turns out this summer was even hotter in parts of town.

Austin records hottest summer on record

We averaged hourly temperature data from Austin-Bergstrom International Airport between Jun. 1 and Aug. 31, the entirety of meteorological summer. 2023 was the hottest meteorological summer on record at the airport, with records dating back to 1942.

2023 was Austin-Bergstrom Intl. Airport's hottest summer on record by far
2023 was Austin-Bergstrom Intl. Airport’s hottest summer on record by far

This summer fell just behind 2011 as the hottest on record at Austin’s Camp Mabry. Average hourly day and night temperatures in Austin were 89.4º, only a tenth of a degree behind our hottest summer in history.

2023 was Austin - Camp Mabry's second hottest on record...barely
2023 was Austin – Camp Mabry’s second hottest on record…barely

Climate change is heating up Austin summers

Though records extend back to 1897, all of Austin’s 10-hottest summers on record have come since 1998.

As the climate warms, Austin’s summer temperatures have warmed by 2.4°F in the last century. We now average 30 100° days each summer — triple the average 100° day count between 1969 and 1999.

100° day count

Thursday was Austin’s 69th 100° day of the summer — a tie for our second-highest triple-digit heat day count on record.

While the summer of 2011 brought an all-time record 90 days at or above 100° in Austin, 14 of those days came in September. As of Aug. 31, 2023’s 100° day count is only seven days behind this point in the year 2011.

The remarkable statistic from this summer is that in 2023, more than half of our triple-digit heat days have been extreme heat days. This year, Austin has tallied 40 days of high temperatures 105° or hotter, whereas 2011 only brought 26 such days.

Austin records driest summer since 1910

Summer 2023 has been near-record dry as well. Between Jun. 1 and Aug. 31, Camp Mabry only recorded 1.31″ of rainfall — only 15% of our normal summer rainfall (8.38″).

Driest summers in Austin history:

  • 0.98″ (1910)
  • 1.31″ (2023)
  • 1.45″ (1934)
Near-record low rainfall this summer in Austin
Near-record low rainfall this summer in Austin

What do we expect in September?

Though a lot of hope for drought relief is being placed in the burgeoning El Niño pattern in the Pacific Ocean, El Niño does not have a strong correlation to increased September rainfall in Central Texas. Most of El Niño’s drought-busting rainfall typically falls locally between December and February.

New outlooks from the National Oceanic and Atmospheric Administration are pessimistic for the coming month, with hotter and drier than normal weather expected to continue for now.

Hotter than normal weather expected in Sept. (NOAA Climate Prediction Center)
Hotter than normal weather expected in Sept. (NOAA Climate Prediction Center)
Drier than normal weather expected in Sept. (NOAA Climate Prediction Center)
Drier than normal weather expected in Sept. (NOAA Climate Prediction Center)

KXAN first warned you this week that although El Niño should bring Texas wetter than normal weather this winter, a nearly equal and opposing force called the Pacific Decadal Oscillation (PDO) may counterbalance that and bring more ‘normal’ rainfall patterns.