San Antonio weather today — Memorial Day — is as close to perfect as late May gets here: mostly sunny skies, a high near 89°F, and calm northeast winds of just 0 to 5 mph. Get outside and enjoy it, because a significant storm system is coming Tuesday night.
Today’s Setup
The Alamo City is clear for takeoff on the holiday. The National Weather Service forecasts mostly sunny conditions with only an 8% rain chance, meaning your backyard BBQ, River Walk stroll, or afternoon at Brackenridge Park is in great shape. Tonight stays comfortable with a low around 70°F and mostly clear skies — a rare treat for late May. Fire up a portable propane grill for the classic Memorial Day cookout; our smoke tri-tip guide will make your neighbors jealous.
Best Window To Be Outside
All day today is yours. Morning is ideal for the trails at Government Canyon State Natural Area or a round of golf before the heat builds toward midday. If you’re hitting the links this week, check the Callaway Big Bertha fairway wood deal — solid timing ahead of summer. The 8% rain chance is essentially noise today, so plan freely.
Storm Threat: Tuesday Night Into Wednesday
Enjoy the calm while it lasts. Tuesday starts manageable — partly sunny, high near 87°F — but the National Weather Service warns that showers and thunderstorms develop after 1 PM CT with a 30% chance. Then Tuesday night, the risk jumps sharply to 90%, and NWS notes “some of the storms could produce heavy rain.” Their Area Forecast Discussion specifically flags strong to severe storms over the Rio Grande Plains Tuesday evening and night, driven by an approaching upper-level trough.
San Antonio sits squarely in Flash Flood Alley. Watch all low-water crossings Tuesday night — if water is over the road, turn around. The River Walk and low-lying areas near Fort Sam Houston and Lackland AFB are worth monitoring. Late week brings relief — the NWS AFD points to warmer, drier conditions returning by late week into next weekend.
Allergy Note
Grass pollen is in full force across the Hill Country corridor this time of year. Keep an allergy relief nasal spray nearby before outdoor activities, and run a HEPA air purifier indoors to keep the air in your home clean after you’ve been outside.
Spurs Game 6 — Thursday at Frost Bank Center
The San Antonio Spurs host the Oklahoma City Thunder in West Conference Finals Round 3 Game 6 at Frost Bank Center on Thursday, May 28. The game is indoors, so weather doesn’t affect play — and Thursday’s forecast looks much better after the midweek storms clear out. Pick up Official team gear on Fanatics and Get tickets on SeatGeek if you still need seats. Go Spurs Go.
Also coming up: Godsmack plays The Rise of Rock World Tour 2026 at Germania Insurance Amphitheater on Friday, May 29 — an outdoor venue. The late-week forecast trends drier, which is good news for amphitheater fans.
Dinner Tonight
A sunny 89°F Memorial Day is made for grilling outside. Keep it simple — throw on whatever’s in the fridge and pair it with cold pasta salad. Need supplies? You can order groceries on Amazon and have everything for tonight’s Memorial Day dinner delivered to your door.
Next Few Days
- Tuesday: Partly sunny, 87°F high; storms after 1 PM CT (30% chance)
- Tuesday night: Heavy storms likely (90%); flash flood risk elevated across the metro
- Wednesday: Active and unsettled; gradual clearing by the latter half of the day
- Late week: Warmer and drier — right in time for Spurs Game 6 and the weekend
Keep an eye on the San Antonio weather forecast page as the storm system approaches Tuesday.
