Lake Tahoe sees second-highest surface temp in 25 years

LAKE TAHOE — One of the United States' most iconic lakes almost saw record-breaking surface level temperatures as another heat wave hits Northern California .

When is warm too warm for Lake Tahoe?

"Too warm, certainly in the case of Lake Tahoe, is when the temperature starts to accelerate the things we don't want in the lake," said Geoff Schladow, UC Davis professor and former director of the Tahoe Environmental Research Center.

Schladow said Lake Tahoe had its second-highest surface temperature recorded from the middle of the lake in the last 25 years on July 22. It was 75.7 degrees.

The highest surface temperature in the last 25 years was on July 24, 2006, at 77.9 degrees.

"Warm water is great for swimming for humans. It's also great for other things we don't want here like aquatic invasive species or harmful algae blooms," said Jesse Patterson, Chief Strategy Officer with Keep Tahoe Blue, said.

A woman went viral on TikTok earlier in July after claiming her dog died after being exposed to Blue-Green Algae while swimming at El Dorado and Nevada Beaches.

The Lahontan Water Quality Control Board tested the water at both beaches and said the results were non-detect for toxins associated with harmful algal blooms.

"Algae that wash up on the beaches is something we don't want. It's also possible warmer temperatures allow for the potential growth of harmful algal blooms," Schladow said.

The results also said the advisory was lifted at El Dorado Beach and is safe for recreational use.

The State Water Resources Control Board released a statement that said in part, "The agencies involved in water-sample testing cannot draw conclusions about the cause of death for the dog from these results; they can only speak to evaluating water quality and the presence of HABs."

Schladow said regardless of how warm it feels, you should always be careful around water because things can change quickly.

"A breezy day can bring really really cold water up from the bottom of the lake and catch people unaware in potentially dangerous situations," Schladow said.

The California Interagency Harmful Algal Bloom-related workgroup is continuing to investigate what caused the death of the dog.