Flash flooding across Bexar County, including San Antonio, on June 12, resulted in 11 confirmed fatalities and over 70 water rescues after intense rainfall overwhelmed drainage systems.
San Antonio International Airport recorded 162 mm (6.37 inches) of rain in 24 hours, its highest June daily total in more than a decade, surpassing the previous record of 83 mm (3.26 inches) set in June 1973. Localized totals of 178–203 mm (7–8 inches) were observed on the Far West Side, Helotes, and in Medina, Comal, Hays, and Guadalupe counties.
Within that period, San Antonio received 142.2 mm (5.6 inches) in just three hours, including nearly 101 mm (4 inches) in a single hour. This amount exceeds the city’s average total June rainfall, which is typically about 76 mm (3 inches).
As a result, the levels of the San Antonio River rose rapidly from about 0.9 m (3 feet) to over 7.6 m (25 feet) in just 2 hours, resulting in severe flooding.
The floods caused at least 11 confirmed deaths and left several people missing as of June 13. According to local media reports, many of the victims were in their cars when a wall of water descended on the area around Northeast Loop 410 and Perrin Beitel Road.
Search and rescue operations are ongoing, with concentrated efforts at Salado Creek near Perrin Beitel and Leon Creek near Highway 90 and Callaghan Road, San Antonio city officials said on June 13.
Over 70 water rescues were conducted by emergency services, including incidents at Beitel Creek and Loop 410, where 19 people were swept into floodwaters and 10 were rescued, some from trees approximately 1.6 km (1 mile) downstream. Dozens of people were hospitalized with injuries ranging from hypothermia to fractures.
Multiple roadways, including Vicar Drive at Beitel Creek and Old O’Connor Road, were washed out or closed indefinitely. Around 30 000 residents experienced power outages, some lasting over 24 hours.
The Olympia Hills Golf & Event Center suffered bridge failures and debris flows, forcing closure through at least June 16. Businesses in low-lying commercial corridors also reported significant flood-related closures and losses.
Meteorologists at the NWS office in San Antonio reported late June 13 that floodwaters from the heavy rains are moving downstream into the Coastal Plains.
“Minor to moderate flooding is forecast along the San Antonio River and Cibolo Creek in Wilson and Karnes counties through this weekend. Remember to turn around, don’t drown!”
According to the National Weather Service (NWS), the event was driven by a quasi-stationary upper-level trough over the region, interacting with record-warm Gulf of Mexico sea surface temperatures. This combination produced exceptionally high atmospheric moisture, with precipitable water values exceeding 50 mm (2 inches), the 99th percentile for early summer in Texas.
This historic flood event is the latest in a long record of significant flooding events that have shaped San Antonio’s approach to flood management and public safety.
In September 1921, remnants of a Gulf hurricane stalled over the city, producing more than 500 mm (20 inches) of rain in just 24 hours. The resulting catastrophic flooding claimed over 200 lives in San Antonio alone and led directly to major engineering projects, including the construction of Olmos Dam and the downtown flood bypass channel, which would later become part of the city’s River Walk system.
In October 1998, a combination of Gulf moisture and stalled frontal boundaries brought 280 mm (11 inches) of rain to the region in less than 48 hours. This event resulted in 31 deaths and nearly USD 1.2 billion in damage (1998 value).
Another notable event occurred in May 2013, when intense convective storms delivered 381 mm (15 inches) of rain within a 12-hour period. Although the death toll was lower, with three fatalities reported, emergency services conducted hundreds of water rescues. This flood prompted further upgrades to San Antonio’s public warning systems and reinforced the importance of timely communication and preparedness in the face of extreme rainfall events.
