textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 1216 AM CDT Sun Aug 23 2026

- Extreme Heat Warning in effect Sunday for portions of the Hill Country, Austin area, and Coastal Plains.

- Potentially dangerous temperatures continue across much of South Central Texas through midweek.

SHORT TERM

(Today through Monday) Issued at 1216 AM CDT Sun Aug 23 2026

Dangerous heat is anticipated today. Forecast highs this afternoon are above 100F for nearly all of South Central Texas with maxima in the 103F to 107F range for many areas. The latest probabilistic blend of models indicates an over 70% chance that many areas straddling the Colorado River will see highs over 105F this afternoon. Several changes were made to our active heat products to reflect this higher confidence in heat potential. An Extreme Heat Warning is now in effect for areas along the TX-71 corridor, including the Austin area and extending into portions of the Coastal Plains. The preexisting Heat Advisory was also expanded to include additional counties along the Balcones Escarpment into the Winter Garden region. Flow in the latest guidance shows slightly backed surface winds compared to Saturday, which could nudge temperatures higher. Moisture mixing may be slightly more favorable Sunday given this orientation but will likely be too marginal to offer much thermal relief. With the nearby low level theta-e ridge axis remaining mostly to our north, the chance of an isolated afternoon shower bringing a slight cooldown is low, with small chances less than 20% limited to the northern Hill Country. Conditions won't be very different as we head into the workweek with little displacement of the current warm continental airmass, remaining hot and dry.

LONG TERM

(Monday night through Saturday) Issued at 1216 AM CDT Sun Aug 23 2026

Little substantive change to the weather pattern is expected for much of the week as strong ridging stays nearly stationary over the southern Rockies into northern Mexico. Temperatures and moisture won't change much with highs staying above 100F for most areas with only a degree or two of day to day variation across the statistical, consensus, and blended models. With high confidence in the heat wave continuing, Heat Advisory products have been extended through Wednesday across much of South Central Texas, and there is some possibility that the heat wave could remain intense after midweek. Later in the week, the core of the dominant ridge slides slightly farther west closer to Arizona. This could provide a little more leeway for an isolated shower or storm to reach our area Thursday or Friday, but the overall setup does not favor much longevity from this potential, and rain chances during that stretch remain generally less than 30 percent for most areas.

AVIATION

(06Z TAFS) Issued at 1216 AM CDT Sun Aug 23 2026

VFR flight conditions prevail. There will be occasional high level clouds that mostly favor overnight into early this morning. Few patchy low clouds are possible as well around or just after sunrise but will not lead to any flight impacts. Winds remain of generally 10 kt or less from the south-southwest to east-southeast in direction. The sea breeze after sunset could help to kick up breezes slightly for the I-35 terminals (KAUS, KSAT, and KSSF) between 01Z and 05Z Monday.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 107 79 106 77 / 0 0 0 0 Austin Bergstrom Intl Airport 105 78 104 77 / 0 0 0 0 New Braunfels Muni Airport 104 76 103 74 / 0 0 0 0 Burnet Muni Airport 103 76 103 74 / 0 0 0 0 Del Rio Intl Airport 105 77 104 77 / 0 0 0 0 Georgetown Muni Airport 105 79 104 77 / 0 0 0 0 Hondo Muni Airport 102 74 101 73 / 0 0 0 0 San Marcos Muni Airport 104 76 103 75 / 0 0 0 0 La Grange - Fayette Regional 105 76 104 77 / 0 0 0 0 San Antonio Intl Airport 104 77 102 76 / 0 0 0 0 Stinson Muni Airport 105 76 104 76 / 0 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning until 7 PM CDT this evening for TXZ171>173- 192>194-208-209-223-225.

Heat Advisory from 7 PM this evening to 7 PM CDT Wednesday for TXZ171>173-192>194-208-209-223-225.

Heat Advisory until 7 PM CDT this evening for TXZ187-189-190-204- 219.

Heat Advisory until 7 PM CDT Wednesday for TXZ191-205>207- 220>222-224.