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UPDATE: Prepare for heavy rainfall Thursday

Some will experience flooding, with isolated spots receiving up to 8″

Rainfall potential from Wednesday through Sunday morning. (Copyright KSAT-12 2026 - All Rights Reserved)

FORECAST HIGHLIGHTS

  • TWO MORE DAYS OF HEAT: Today, Wednesday will still see highs in the mid-90s
  • WHEN WILL RAIN BEGIN?: Isolated chances Wednesday, rainfall becomes likely on Thursday
  • HOW MUCH?: 2-5″ possible, however, isolated spots could see more than 6″ of rainfall
  • WHEN WILL RAIN END?: Rain will become lighter over the weekend, with chances ending late Sunday

FORECAST

TODAY -- GENERALLY QUIET

Temperatures will soar again today into the mid-90s, with humidity and partly cloudy skies. A shower can’t be ruled out this afternoon, mainly east of I-35.

WEDNESDAY (9/30) -- STORMS OUT WEST

Wednesday will be a transition day, as the storm system pulls into the Texas. A few showers will be possible Wednesday morning along the Rio Grande. Then, by Wednesday afternoon, storms will take shape west of San Antonio along a slow-moving front. A few of these storms could be strong to severe. As the storms move east, heavy rainfall will become the bigger threat.

Future radar for Wednesday night (9/30) at 9pm. (Copyright KSAT-12 2026 - All Rights Reserved)

THURSDAY (10/1) -- HEAVY RAIN LIKELY

The front will slowly make its way toward San Antonio on Thursday, with storms almost a sure bet by Thursday afternoon. Heavy rainfall and street flooding is a risk. Abundant moisture and training of storms could create isolated rainfall of 6″+ somewhere across the area. However, most will see totals in the 2-5″ range.

Future radar for Thursday afternoon (10/1) at 4pm (Copyright KSAT-12 2026 - All Rights Reserved)

Rainfall potential from Wednesday through Sunday morning. (Copyright KSAT-12 2026 - All Rights Reserved)

FRIDAY (10/2) -- RAIN LIKELY

The front should slowly move south and east, pushing the threat for the heaviest rainfall south of San Antonio on Friday. However, showers and a storm or two is still possible during the day on Friday. Any additional rainfall could aggravate flooding issues.

THIS WEEKEND -- LIGHTER RAIN, LOWER CHANCES

Lighter rainfall is expected over the weekend, before chances come to an end early next week.

Extended Forecast (Copyright KSAT-12 2026 - All Rights Reserved)

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