Near 100° for San Antonio this week, and Tropical Storm Bertha

Also, flood risk continues along lower Nueces and Frio Rivers near Cotulla and Tilden

Sarah Spivey, KSAT Weather Authority Meteorologist

Justin Horne, KSAT Weather Authority Meteorologist

Adam Caskey, KSAT Weather Authority Meteorologist

Published: July 20, 2026 at 8:59 PM

FORECAST HIGHLIGHTS

HOT DAYS AHEAD: Triple digits possible by Wednesday
NUECES & FRIO FLOODING: Cotulla and Tilden will experience major flooding soon
TROPICAL STORM BERTHA: Some strengthening possible. Odds currently favor minimal/no impacts for Texas
AQUIFER/LAKES STILL RISING: Aquifer tops 650′ for the first times since 2022

FORECAST

FIRST TRIPLE DIGITS OF THE YEAR FOR SA?

We’ve managed to avoid triple digits this year. This week, however, it may be hard to dodge a late-July heat wave. Temperatures will rise, with peak temperatures on Wednesday. As of now, we are forecasting 100° in San Antonio. Heat indices will reach the low-100s.

TROPICAL STORM BERTHA

A tropical system has formed in the Gulf. Some strengthening is expected today and it could receive a name: Bertha. While there is still some uncertainty with Bertha’s future, we are getting more clarity. TS Bertha likely affects the New Orleans area tomorrow into Wednesday. From there, it will encounter more wind shear, dry air, and possibly interact with land, which all should significantly weaken the system.

The leftovers then make a run at South Texas during the second half of the work week. That means impacts to San Antonio and surrounding areas would be minimal (if any). That said, as it is with tropical systems, much can change over the next 48 hours, so stay tuned for more updates.

COTULLA/TILDEN

While it has yet to flood along the Nueces and the Frio near Cotulla and Tilden, floodwaters will rise soon. These locations need to be on high alert through the weekend.

AQUIFER/LAKES STILL RISING!

While our bodies of water are starting to level out, we’re still noticing small rises in area lakes and the aquifer. Canyon Lake is now 99% full, while Medina has reached 27% capacity. The Edwards Aquifer at the J-17 well is now above 650′ for the first time in more than 4 years!