textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 1236 PM CDT Mon Aug 17 2026

- Hot and rain free conditions persist. The humidity and heat risk to slowly uptick for the second half of the week into weekend. Practice heat safety.

SHORT TERM

(Tonight through Tuesday night) Issued at 1236 PM CDT Mon Aug 17 2026

Hot and sunny conditions prevail today with the likely lowest dew points of the week during peak daytime heating this afternoon. The highs will again climb into the 100 to 103 degree range for most except for the cooler favored areas across the Hill Country and Southern Edwards Plateau. The peak heat indices with the drier air maintain near or slightly above the ambient temperature. The dew points will recover overnight, as it does most nights, but are not forecast to mix down as well on Tuesday afternoon as compared to this afternoon. The dew points are actually forecast to mix out better for Wednesday afternoon than Tuesday afternoon for most. It is difficult to discern the main difference but when looking at the 850-700 mb layer, Tuesday afternoon does seems to favor a more southeasterly oriented flow across that layer while today is more easterly across that layer and Wednesday afternoon then turns more southerly to south-southwesterly within that layer. Overall as a result, while the ambient temperatures look to remain of within a degree or so of the highs today, Tuesday afternoon will likely see the highest heat indices out of the next three days. The coastal plains could see some locations in the 106 to 109 degree range. Outside from some scattered low clouds and perhaps a little bit of patchy fog in the coastal plains tonight into Tuesday morning, a mostly to completely clear sky prevails.

LONG TERM

(Wednesday through next Monday) Issued at 1236 PM CDT Mon Aug 17 2026

The weather regime remains similar for the second half of the week through the weekend. The region remains under the influence of the sub-tropical ridge, which will begin to amplify across the Four Corners region before gradually sliding back southeastward towards Texas this weekend. Surface high pressure also maintains over the Gulf and yields a persistent light to modest south-southeasterly flow across the region. Hot daytime high temperatures, most in the 100 to 103 degree range outside of the cooler terrain influenced regions, will continue with little day to day fluctuation. However, with the subtle day to day increase in the low-level moisture and humidity beyond Wednesday, expect for the peak heat indices and overall heat risk to slowly rise. We'll closely analyze values towards the short term, as the NBM has been a little too high with dew points beyond the day 4 period regarding mixing through the afternoon periods, but enough of the region may see the heat risk climb with combination of the temperature/heat indices for the possible need of heat advisories at some point. Conditions look to remain rain free otherwise with development of morning low clouds eroding to mostly sunny skies each afternoon.

AVIATION

(18Z TAFS) Issued at 1236 PM CDT Mon Aug 17 2026

VFR conditions are expected through the period across all forecast terminals. Southerly winds today will eventually turn light and variable overnight before picking back up from the south generally around or under 10 knots. There is the potential for MVFR CIGS overnight at KSAT and KSSF however confidence is quite low as most model ensembles keep VFR CIGS. Decided to keep mention out of this forecast package for now but future packages may need to add this in based on newer model guidance. We will continue to monitor and amend as needed.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 77 102 78 102 / 0 0 0 0 Austin Bergstrom Intl Airport 76 101 78 101 / 0 0 0 0 New Braunfels Muni Airport 75 100 76 101 / 0 0 0 0 Burnet Muni Airport 74 100 76 99 / 0 0 0 0 Del Rio Intl Airport 77 101 77 102 / 0 0 0 0 Georgetown Muni Airport 76 101 78 100 / 0 0 0 0 Hondo Muni Airport 74 100 74 101 / 0 0 0 0 San Marcos Muni Airport 75 100 76 100 / 0 0 0 0 La Grange - Fayette Regional 76 100 77 101 / 0 0 0 0 San Antonio Intl Airport 77 101 77 101 / 0 0 0 0 Stinson Muni Airport 77 101 77 102 / 0 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

None.