Today is a prime example of why you can't just glance at the sky and call it a day. That clear blue? It's lying to you about the heat trying to kill your workout.
- The Heat is ON, Seriously: We're under Extreme Heat Warnings and Heat Advisories across the I-35 corridor, with heat indices hitting a brutal 108-109°F. Your body doesn't care how clear the sky is when it's actively trying to boil you.
- Air Quality's Holding Up, Mostly: The AQI is hanging in the good range at 43, with the dominant pollutant being ozone, generally at the "upper end of the 'Good' range" in San Antonio. So your lungs might be okay with the air itself, but they'll be working overtime to cool you down from the heat.
- Pollen's a PITA: Ragweed is moderate today, which means your seasonal allergies might decide to join you on your run.
- Trail Trouble Ahead: Several popular greenway segments are dealing with closures and construction.
The HeatDome is Real – Stay Indoors or Get Out Early
Look, I love hitting the trails as much as the next guy, but when the National Weather Service is throwing around terms like "dangerous heat" and "heat stroke is an emergency, call 911," you need to listen. We're looking at actual temperatures climbing to 101°F today. That's not just "warm," that's "re-evaluate your life choices" hot for any strenuous activity.
Extreme Heat Warning: Reschedule Your Strenuous Workout
Seriously. If you absolutely MUST be outside, aim for before 8 AM or after 8 PM, stay in the shade, and hydrate aggressively. The NWS advises rescheduling strenuous activities to early morning or evening. Wear lightweight, loose-fitting clothing. Know the signs of heat exhaustion and heat stroke. Don't be that person wheeled off the Salado Creek Greenway by EMS because you thought you were tougher than a Texas August.
Breathing Easy? Mostly.
The good news is our air quality isn't compounding the problem. With an AQI of 43, it's generally good for most folks. But here's the kicker: AccuWeather is still showing our AQI as "Poor" and "unhealthy for sensitive groups" today. While other sources are more optimistic, if you've got any kind of respiratory sensitivity, that discrepancy alone should give you pause. Don't push it if you feel any irritation.
Moderate Pollen Alert: Ragweed on the Rise
Ragweed is being a jerk today, sitting at moderate levels. If you're an allergy sufferer, expect potential sneezing, runny nose, or itchy eyes. Consider an antihistamine or sticking to indoor workouts to avoid the misery.
Trail Closures and Other Nuisances
If you're planning a long haul on one of our beloved greenways, you need to check your route. The City of San Antonio Parks & Recreation department has ongoing closures. For example, portions of the Salado Creek Greenway are currently closed for repair work south of the Southside Lions Park entrance until October, and another section from Gembler Road to Houston Street is closed indefinitely. There are also periodic closures on the Salado Creek Greenway near the Tobin Park Trailhead due to TxDOT construction.
And for those who like to explore our natural spaces:
Wasp Nests Reported at Confluence Park
Active wasp nests have been sighted near the pavilion at Confluence Park as of yesterday. Exercise extreme caution and avoid disturbing any vegetation in that area. Nobody wants to finish their run with a swarm of angry wasps.
Data grounded with National Weather Service Austin-San Antonio, San Antonio River Authority, Airmine, and City of San Antonio Parks & Recreation from August 25, 2026.