Heat stress in San Antonio
Hot, humid South Texas summers with long stretches of high heat stress.
Reduce exertion and hydrate frequently. Take regular breaks somewhere cooler.
Wet-bulb globe temperature via the Liljegren (2008) method. This page is cached and refreshes in the background, so the live badge below can be a few minutes ahead of it.
View San Antonio on the live mapComfortable in short stretches. Take a break somewhere cooler each hour of activity, drink before you feel thirsty, and keep anything strenuous short. Never leave children or pets in a parked car.
Screening guidance from ACGIH TLV, GHSA/KSI/NATA, and TB MED 507. WBGT is a composite index, not air temperature. These are acclimatized-population defaults — the unacclimatized, older, ill, or those on certain medications are at higher risk. Not a substitute for a required on-site WBGT reading or your employer / league / command policy.
Reading heat stress in San Antonio
Wet-bulb globe temperature (WBGT) is the heat measure that actually tracks danger to the body. Unlike the plain air temperature on your phone, it folds in humidity, wind, and direct sun — the factors that decide whether your sweat can still cool you. It’s the standard the military, athletic associations, and occupational-safety bodies use to call when outdoor activity is no longer safe.
That matters in San Antonio because hot, humid South Texas summers with long stretches of high heat stress. The number above is the live outdoor WBGT for the city right now; tap through to the live map to inspect any neighborhood, scrub the forecast hour by hour, and see the 7-day outlook.
How hot San Antonio usually gets
Across 2015–2024, San Antonio averaged a 95°F daily high in summer — higher than most cities we track, and August is typically the warmest month.
Humidity is the real story here — summer averages about 65%, so sweat evaporates poorly and heat stress runs well above what the temperature alone suggests.
Daily high temperatures and humidity from ERA5 reanalysis, 2015–2024 (hottest day in the sample: 2023-08-09). These are climate averages for context — the reading at the top of this page is the live one.
Heat in San Antonio: common questions
How hot does it usually get in San Antonio?
Across 2015–2024, San Antonio averaged a 95°F daily high through summer, with about 105 days a year at or above 90°F and 17 at or above 100°F. August is typically the hottest month, and the hottest day in that sample reached 107°F. Figures are from ERA5 daily reanalysis.
When is the hottest time of year in San Antonio?
August has the highest average daily high in San Antonio. Humidity is the real story here — summer averages about 65%, so sweat evaporates poorly and heat stress runs well above what the temperature alone suggests. Use the forecast on this page to plan around the specific days that matter.
What is the WBGT in San Antonio right now?
The reading at the top of this page is the current wet-bulb globe temperature for San Antonio, Texas, computed from live weather by the Liljegren (2008) method and labelled with how recently it updated. For an exact reading at your own neighbourhood, plus an hour-by-hour forecast, open the live map.
Why is WBGT more useful than the temperature for San Antonio?
Air temperature ignores humidity, wind, and sun — the things that decide whether heat is dangerous. San Antonio's climate (hot, humid South Texas summers with long stretches of high heat stress.) is exactly why a single "feels-like" or thermometer reading can understate the real risk. WBGT captures all of it in one number.
When is heat most dangerous in San Antonio?
Heat stress typically peaks in the early-to-mid afternoon, when sun load is highest. Plan strenuous outdoor activity for early morning or evening, hydrate ahead of time, and use the forecast scrubber on the live map to find the safest window.
Is WetBulbTracker free to use for San Antonio?
Yes. WetBulbTracker is free, needs no account, and works for anywhere on Earth — not just San Antonio. You can install it to your home screen and even set heat alerts.
Put San Antonio’s live heat stress on your site
A self-updating WBGT badge for schools, teams, camps, and local sites — it always shows the current reading and links back here.
<iframe src="https://wetbulbtracker.com/embed/san-antonio-tx" width="340" height="150" style="border:0" title="Live WBGT — San Antonio, TX" loading="lazy"></iframe>Paste it into any website. The badge updates itself and links back here. Add ?theme=light for light sites.