Key Takeaways
- South Texas, especially San Antonio, is receiving its first notable rainfall in months, with 0.99 in recorded at the airport over the weekend.
- Monday will bring scattered showers and thunderstorms, most intense from mid‑afternoon to early evening (3‑9 p.m.), when rain chances rise to 60‑80 % and periods of moderate‑to‑heavy rain could last several hours.
- The National Blend of Models forecasts 1‑2 in of rain across the San Antonio area through Tuesday, with isolated pockets potentially seeing 3‑4 in or more, mainly in the Hill Country and along the I‑35 corridor.
- Although severe thunderstorms (large hail, damaging winds) are unlikely, isolated flooding is possible where higher totals occur; the NWS has issued a Level 1 (of 4) excessive‑rainfall risk for the region.
- Temperatures will stay well below average Monday, with highs only in the low‑60s °F, then gradually warm back into the low‑80s °F by Wednesday as southerly flow returns.
- Rain chances taper off Tuesday afternoon, with only a 20‑30 % probability of lingering showers Wednesday and a ~20 % chance of isolated pop‑up storms Thursday‑Friday.
South Texas is finally experiencing rain that could make a dent in the long‑running drought. At San Antonio International Airport, 0.99 inch fell from Saturday night through Sunday – the highest two‑day total the city has seen in nearly six months, since 1.19 inches were recorded on Oct. 24‑25. More precipitation is on the way as an atmospheric disturbance moves northward from the Rio Grande, setting the stage for another round of potentially heavy rain on Monday.
Monday’s forecast calls for scattered showers and thunderstorms to develop across parts of South and Central Texas early in the morning. While rain chances in San Antonio start near 40 % at 7 a.m., they increase modestly by mid‑ to late‑morning. The activity will not be steady; instead, the city should expect off‑and‑on periods of moderate rainfall throughout the day. Radar imagery shows widely scattered storms evolving, with the most widespread rain expected from the mid‑afternoon through the evening, specifically between 3 p.m. and 9 p.m. During this window, rain probabilities climb to 60‑80 % and storms could persist for several hours, delivering moderate to heavy downpours. This timing coincides with the Texas Cavaliers River Parade, which begins at 7 p.m. in downtown San Antonio, so attendees should prepare for wet conditions.
Despite the rain, the threat of severe thunderstorms remains low. The National Weather Service indicates that large hail and damaging winds are unlikely, though most storms will still produce thunder, lightning, and occasional intense bursts of rain. Temperatures on Monday will be unusually cool for the season: morning lows in the mid‑50s °F will rise only into the low‑60s °F by afternoon, roughly 20 degrees below the typical high for this time of year.
A second wave of scattered showers and thunderstorms is possible early Tuesday morning and may linger into the afternoon. Heavy rain remains a possibility, but the hail risk stays minimal. The NWS has placed San Antonio and surrounding areas under a Level 1 (of 4) risk of excessive rainfall, meaning isolated flooding could occur where higher rain totals fall, though widespread flooding is not anticipated.
Quantitatively, the National Blend of Models projects 1‑2 inches of rain for the San Antonio metro area through Tuesday. However, isolated higher totals of 3‑4 inches or more are not out of the question, particularly in the Hill Country and along the I‑35 corridor. For most residents, flooding will not be a widespread issue, but pockets receiving three inches or more could experience localized water‑accumulation problems. The Level 1 excessive‑rainfall risk underscores that while the overall flood threat is modest, vigilance is warranted in low‑lying areas and near creeks.
By the latter part of Tuesday, rain chances will begin to decline. Temperatures will stay below average, with highs climbing only into the upper‑60s to low‑70s °F. Southerly flow will return on Wednesday, ushering warmer air back into the region and pushing high temperatures into the low‑80s °F. A few lingering showers may persist, but rain probabilities will drop to 20‑30 %. Thursday and Friday are expected to be even warmer, with highs reaching 85‑87 °F and only a ~20 % chance of isolated pop‑up thunderstorms. Overall, the coming days will provide a much‑needed moisture boost for drought‑stricken South Texas, followed by a gradual return to typical warm, dry conditions.