July weather recap: Record-breaking rainfall, South Central Texas rivers reach historic crests

Although July is seasonally hot in San Antonio, July 2025 was average, and notably humid—a result of saturated soils from heavy rainfall, fueling evaporation and transpiration into the air.

Temperatures

Overall, San Antonio endured a classic July heat wave, amplified by humidity that followed unprecedented rainfall earlier in the season.

Rainfall after July 4 briefly cooled the region, as rain-cooled air settled in.

• Warmest afternoon: 100 degrees

• Coolest morning: 67 degrees

Hill Country flooding

The deadly flood stemmed from remnants of Tropical Storm Barry, which stalled over Central Texas and combined with an upper‑level low to unleash repeated “training” rain bands.

Showers and thunderstorms stalled in some areas. A total of 20.3″ of rain fell over the July 4–7 period, equivalent to several months’ worth of precipitation concentrated into hours.

The Guadalupe River near Hunt surged roughly 22 feet in about two hours, reaching record levels and sweeping through communities including Camp Mystic, where dozens of young campers died.

A secondary low dropped another 8–10 inches, particularly affecting the Frio and Llano River basins.

Major rivers throughout South Central Texas—Guadalupe, Medina, Llano, Colorado, Frio, Rio Grande, and Nueces basins—all flooded in mid‑July, producing historically high crests across multiple counties.

Looking ahead to August

July was a month defined by historic rainfall and flooding in the Hill Country early on, followed by humidity in San Antonio through the rest of the month.