Austin myth busted (sort of): The truth about Barton Springs temp

Long-held belief that pool water holds 68 degrees year-round just isn’t true, data shows


Spoiler: The water temperature at Barton Springs isn’t 68 degrees, and rarely has it been.

Hydrogeologist David Johns checked temperatures at three locations at the spring-fed swimming pool recently.

A probe monitored by the USGS measures the temperature every 15 minutes and records it online.

A jump into Barton Springs Pool raises goosebumps and turns lips blue. That’s what 68-degree year-round water does to a body, right?

Not so fast.

Despite T-shirts that proclaim it, websites that tout it and a Wikipedia entry that boasts it, the water temperature at Barton Springs isn’t 68 degrees, and rarely has it been.

We headed to the pool recently with David Johns, a hydrogeologist for the City of Austin, and his assistant, Walker Stone, to dunk a multi-sensor probe into three locations at the spring-fed swimming pool and let science do the talking.

Our results? At the fault line next to the diving well, near the main spring, the temperature read 70.6 degrees. But at the surface by the downstream dam, it was 71.6 degrees. It was even warmer at the shallow end of the pool, where it measured 74.9 degrees.

Myth busted, then? Sort of.

RELATED: Have you ever swum naked at Barton Springs?

The pool has, at times, measured 68 degrees. But it’s not all that common, and certainly not during the summer, when most people are taking that polar bear plunge. The temperature varies slightly, depending on time of year and discharge volume. Mostly, it depends on what season rains fall.

Barton Springs is fed by a karst aquifer, and rain that falls in its recharge zone moves rapidly to the springs. When it rains during the winter, water entering the aquifer is already chilly — about 50 or 55 degrees — making the water that emerges from the springs cooler. If rain falls and creeks flow in the summer, the water soaks in at a much warmer temperature, and the spring’s flow is warmer.

For years, the City of Austin website stated that the pool’s water temperature hovered around 68 degrees year-round. Today the website claims an “average temp of 68 to 70.” That’s still not quite accurate, but closer than the Wikipedia entry for the pool, which boldly states, “The pool is a popular venue for year-round swimming, as its temperature maintains a stable 68 °F (20 °C) in the winter and summer.”

“I was talking to someone just the other day who said it was 68 degrees. I had to bite my tongue. It’s an urban myth,” said Johns, ever the scientist.

Need more evidence? Sensors in an opening at the bottom of the pool near the main springs that are now monitored by the USGS have automatically taken a temperature reading every 15 minutes since 1993. That’s typically the coolest spot in the pool during the summer, and the temperature there has held a consistent 70.5 degrees for the past few weeks. It hasn’t dropped below 70 since April.

RELATED: What are the best swimming holes in Central Texas?

“Some people say it seems colder than that, but it’s still 30 degrees colder than body temperature, so it’s cold,” Johns says.

Nobody really knows how that 68-degree myth got started. Maybe the temperature actually did measure 68 one day when someone took a reading. It wasn’t steady, though, and it wasn’t year-round. Johns suspects someone at the city settled on 68 for nothing other than it sounded good. “Sixty-eight sounded cooler and more hip than 70,” he said.

As Johns prowled Barton Springs on our visit, more than a few swimmers howled as they submerged themselves in chilly water. Renee Epstein shivered as she waded out of the shallow end.

“It’s very cold,” Epstein said. “My guess is 58 degrees.”

John Longoria and Rob Borromeo pegged it at a little warmer, somewhere between 65 and 68, then cannonballed into the pool. When they heard what Johns’ temperature probe read, they laughed.

“Check your instruments!” Longoria shouted from the water.

If you still get goosebumps when you leap in, don’t worry. You’re not alone.

“For you and me, it’s still bracing,” Johns says.

Reader Comments ...

Next Up in Lifestyle

Where are they now? Fazal Ahmad family
Where are they now? Fazal Ahmad family

Mukhtar Abdul Jabbar, 20, a refugee from Afghanistan by way of Pakistan, is soon going to be able to better support his family — mother Uliya Fazal Ahmad, 49, and siblings Palwasha, 18, Nisar, 17, Nazi, 16, and Feroza, 13. The Fazal Ahmad family — Mukhtar Abdul Jabbar, left, Feroza Abdul Jabbar, Palwasha Abdul Jabbar, , Uliya...
New research done in Austin helping more women get and stay pregnant
New research done in Austin helping more women get and stay pregnant

Couples trying to get pregnant, there’s even more hope on the horizon. At the recent American Society for Reproductive Medicine Scientific Congress & Expo in San Antonio, doctors and scientists presented their research. Seven of those studies were being done here at Texas Fertility Center. “We’re excited...
Where are they now? Vasquez Olais family
Where are they now? Vasquez Olais family

This year,  Keila Vasquez, 20, was able to start school at Avenue Five Institute to become a cosmetologist. “It was something I wanted to do since I was young,” she says. She’ll be through with school in about eight months, which will help her support her family — partner Luis Olais, 22, and...
Where are they now? Noheli family
Where are they now? Noheli family

This year Issa Noheli, 63, received something he had dreamed about:  a prosthetic leg. He lost his leg 20 years ago in an attack on his Rwandan refugee camp. He is working with a physical therapist to learn how to walk better with his new leg. March, he received his first-ever prosthetic leg from the Hanger Clinic...
Need a pre-feast calorie burn? Do a turkey trot!
Need a pre-feast calorie burn? Do a turkey trot!

The annual ThunderCloud Subs Turkey Trot takes place Thursday. Runners make their way across the First Street Bridge in this 2012 file photo by Alberto Martinez AMERICAN-STATESMAN   Before you sit down to a Thanksgiving feast, we recommend some pre-emptive calorie burning. One of the most fun ways to do that? A turkey...
More Stories