San Antonio started Friday wrapped in muggy air and mostly clear skies, with temperatures hovering near 67°F at Kelly Field and an afternoon high near 87°F expected under partly sunny skies. The pleasant start is misleading, though: the big story is the looming heavy rain and flash flooding. A Flood Watch is posted from Friday evening through Monday evening, May 25, with storm chances climbing Saturday into Memorial Day weekend. A few showers may pop up in the morning, but the real concern is later, when downpours could turn low‑lying streets and creek crossings into dangerous trouble spots. If you are hitting the road for the long weekend, keep an eye on updated forecasts and never try to drive through flooded roads.
What To Expect This Weekend
The NWS Austin/San Antonio has a Flood Watch in effect from Friday evening through Monday evening and warns that many spots could pick up 2 to 4 inches of rain, with isolated pockets seeing as much as 6 inches. Saturday carries the highest odds for widespread showers and storms, and forecasters caution that repeated rounds of heavy rain may trigger rapid runoff and localized flash flooding. High temperatures should stay in the low to mid 80s, with sticky overnight lows holding near the low 70s.
Timing And Local Impacts
Hour by hour, forecasters see a chance of rain showers before about 7 a.m. Friday, followed by a warm, partly sunny afternoon. Tonight brings a slight chance of showers and thunderstorms, mainly between 10 p.m. and 1 a.m. Saturday. The weekend is when coverage and intensity really ramp up, and localized downpours could drop an inch or more of rain in a short burst, overwhelming storm drains and low‑water crossings. Earlier this month, a May 1 Flood Watch snarled the morning commute; check out our morning commute swamped coverage for a reminder of how quickly things can go sideways on the roads.
How To Prepare
Do not drive through standing water; the old saying “Turn Around, Don’t Drown” exists for a reason. If you live in a flood‑prone area, move valuables off low floors, and remember that the City of San Antonio posts maps, alerts, and street‑closure information online. Keep phones charged, postpone nonessential trips during heavy rain, and have an emergency kit ready in case you need to head for higher ground. Before you head out, monitor the city’s alert page and the National Weather Service for any new Flood Warnings or road closures.
