San Antonio woke Monday, July 13, 2026 to cloudy, muggy skies, with temperatures starting near 80°F and a daytime high headed for about 91°F. The bigger story is what comes next, as a multi-day stretch of showers and thunderstorms is set to kick off tonight, bringing locally heavy downpours and pockets of flash flooding through Thursday.
Tonight's Threat And The Evening Commute
Forecasters expect showers and thunderstorms to start popping Monday evening, with a chance between about 7:00 p.m. and 10:00 p.m. on Monday, July 13, then a higher likelihood from roughly 10:00 p.m. to 1:00 a.m. Tuesday, July 14. Periods of rain are expected to continue overnight. Lows should hold near 76°F with sticky conditions, and the forecast discussion notes heat index readings up to about 101°F while storms develop. Many spots could see new rainfall amounts of a quarter to a half-inch to start.
According to the National Weather Service Austin/San Antonio, the best chances for heavy rain run from Monday night through Thursday, and forecasters caution that "a Flood Watch could be needed" for parts of the region if the wetter scenarios play out.
How Much Rain Could Fall
Rain totals will depend heavily on which neighborhoods get parked under the slow movers, but forecasters warn that sluggish thunderstorms could drop multiple inches of rain in a short time. Guidance cited in the updated forecast discussion points to several-day totals of 2–6 inches from Monday through Thursday for many locations, with isolated pockets near 8 inches possible where storms stall.
The heaviest threat is most likely over the Rio Grande Plains and the southern Edwards Plateau. Still, low-lying and poor-drainage neighborhoods inside Bexar County are being urged to stay alert for rapid ponding and quick street flooding when the heavier cells roll through.
Local Actions And Resources
If you have plans this week, expect soggy conditions and potential slowdowns for outdoor events and evening commutes. It is a good idea to build in extra travel time and keep an alternate route in your back pocket. The city is reminding residents not to drive through flooded roadways and to sign up for local alerts. For safety tips and road-closure information, check guidance from the City of San Antonio.
We flagged this building pattern in our earlier flood-risk outlook. This update underscores the increased odds of heavier rain and the growing possibility that a Flood Watch could be issued.
Weekend Outlook
By the weekend, forecasters expect drier weather to return, with highs climbing back into the low 90s on Saturday, July 18, 2026 and Sunday, July 19, 2026. If the midweek storms end up being as widespread as advertised, plan on damp mornings and soggy ground lingering into any outdoor weekend activities.
