Heat Advisory — Williamson, TX, Hays, TX, Travis, TX, Bastrop, TX, Lee, TX, Bexar, TX, Comal, TX, Guadalupe, TX, Caldwell, TX, Fayette, TX, Atascosa, TX, Wilson, TX, Karnes, TX, Gonzales, TX, De Witt, TX, Lavaca, TX 7:00 PM Heat Advisory — Williamson, TX, Hays, TX, Travis, TX, Bastrop, TX, Lee, TX, Bexar, TX, Comal, TX, Guadalupe, TX, Caldwell, TX, Fayette, TX, Atascosa, TX, Wilson, TX, Karnes, TX, Gonzales, TX, De Witt, TX, Lavaca, TX 7:00 PM

Williamson County, Texas, United States

Last updated: 3:50 PM CDT  ·  Refresh
36°C
Feels like 39°
Mostly Clear
▲ 37°  /  ▼ 24°
Wind
12 mph S
Humidity
39%
Dew Point
21°
Pressure
29,23 inHg
Visibility
10 mi
UV Index
7,9
Cloud Cover
30%
Sunrise
7:13 AM
Sunset
7:38 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Williamson County is currently mostly clear at 36°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 2286 J/kg) — isolated convective development possible. Sunrise: 7:13AM · Sunset: 7:38PM.

Alerts

Heat Advisory
Williamson, TX, Hays, TX, Travis, TX, Bastrop, TX, Lee, TX, Bexar, TX, Comal, TX, Guadalupe, TX, Caldwell, TX, Fayette, TX, Atascosa, TX, Wilson, TX, Karnes, TX, Gonzales, TX, De Witt, TX, Lavaca, TX
Expires 7:00 PM
Heat Advisory
Williamson, TX, Hays, TX, Travis, TX, Bastrop, TX, Lee, TX, Bexar, TX, Comal, TX, Guadalupe, TX, Caldwell, TX, Fayette, TX, Atascosa, TX, Wilson, TX, Karnes, TX, Gonzales, TX, De Witt, TX, Lavaca, TX
Expires 7:00 PM
31 AQI · Good Dominant: O3 Air Quality
Hourly Forecast · Next 24 Hours
Now
36°
4%
4 PM
37°
8%
5 PM
36°
8%
6 PM
33°
8%
7 PM
31°
8%
8 PM
29°
8%
9 PM
29°
5%
10 PM
29°
5%
11 PM
28°
5%
12 AM
28°
3%
1 AM
27°
3%
2 AM
27°
3%
3 AM
27°
3%
4 AM
26°
5%
5 AM
24°
5%
6 AM
23°
5%
7 AM
24°
5%
8 AM
26°
5%
9 AM
27°
5%
10 AM
29°
3%
11 AM
29°
3%
12 PM
30°
3%
1 PM
32°
3%
2 PM
33°
3%
7-Day Forecast
Today
37° 24°
Mostly Clear.
Mon
38° 24°
Mostly Clear.
Tue
39° 23°
Clear.
Wed
36° 25°
Overcast with a 44% chance of rain.
Thu
37° 23°
Drizzle, 43% chance.
Fri
37° 23°
Clear.
Sat
37° 22°
Clear.
TimeTempConditionsPrecipWindHumidity
Now 36° Mostly Clear 4% 12 mph S 39%
4 PM 37° Partly Cloudy 8% 12 mph SSE 42%
5 PM 36° Partly Cloudy 8% 13 mph SSE 47%
6 PM 33° Partly Cloudy 8% 17 mph SSE 55%
7 PM 31° Partly Cloudy 8% 16 mph SSE 62%
8 PM 29° Partly Cloudy 8% 14 mph SSE 65%
9 PM 29° Mostly Cloudy 5% 12 mph SSE 68%
10 PM 29° Mostly Cloudy 5% 12 mph S 70%
11 PM 28° Mostly Cloudy 5% 10 mph S 73%
12 AM 28° Partly Cloudy 3% 10 mph S 75%
1 AM 27° Partly Cloudy 3% 9 mph S 78%
2 AM 27° Partly Cloudy 3% 8 mph S 80%
3 AM 27° Partly Cloudy 3% 7 mph S 83%
4 AM 26° Partly Cloudy 5% 6 mph S 84%
5 AM 24° Partly Cloudy 5% 5 mph S 85%
6 AM 23° Partly Cloudy 5% 5 mph S 86%
7 AM 24° Partly Cloudy 5% 5 mph S 83%
8 AM 26° Mostly Clear 5% 6 mph S 76%
9 AM 27° Mostly Clear 5% 7 mph S 71%
10 AM 29° Mostly Clear 3% 7 mph S 68%
11 AM 29° Mostly Clear 3% 8 mph S 65%
12 PM 30° Partly Cloudy 3% 8 mph S 63%
1 PM 32° Partly Cloudy 3% 8 mph S 59%
2 PM 33° Mostly Clear 3% 9 mph S 55%
15-Day Forecast
Today
9/13
Mostly Clear
8%
24°
37°
Mon
9/14
Mostly Clear
5%
24°
38°
Tue
9/15
Clear
3%
23°
39°
Wed
9/16
Overcast
44%
25°
36°
Thu
9/17
Drizzle
43%
23°
37°
Fri
9/18
Clear
3%
23°
37°
Sat
9/19
Clear
19%
22°
37°
Sun
9/20
Clear
60%
23°
36°
Mon
9/21
Drizzle
60%
23°
36°
Tue
9/22
Drizzle
60%
20°
34°
Wed
9/23
Drizzle
60%
21°
34°
Thu
9/24
Drizzle
60%
22°
33°
Fri
9/25
Drizzle
60%
22°
33°
Sat
9/26
Drizzle
60%
21°
33°
Sun
9/27
Drizzle
60%
21°
33°
31
Good
U.S. Air Quality Index · Dominant: O3
50 100 150 200

Air quality is satisfactory and poses little or no health risk.

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
29 AQI 5.2 µg/m³
O3
Ground-level ozone
Dominant
31 AQI 34 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Mon 31 Good 31 29
Tue 31 Good 31 22
Wed 39 Good 33 39
About the Air Quality Index
0–50 Good
51–100 Moderate
101–150 Unhealthy for Sensitive Groups
151–200 Unhealthy
201–300 Very Unhealthy
301–500 Hazardous

The U.S. AQI runs 0–500. The overall value equals the highest individual pollutant sub-index, and the dominant pollutant is the one driving it. PM2.5 (fine particles) is reported in µg/m³ and ozone (O3) in ppb. Forecast source: NWS NAQFC.

1000850700500400300250200150100 -40-30-20-10010203040 0.41247101624 LCLLFCEL0°C Temperature (°C) Pressure (hPa)
Temp Dewpoint Parcel (SB) CAPE CIN Dry adiabat Moist adiabat Mixing ratio
RAP
Valid dim. sept. 13, 19:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE2545 J/kg
MLCAPE1835 J/kg
MUCAPE2545 J/kg
SBCIN-0 J/kg
MLCIN-15 J/kg
Lifted Index-4.3
Kinematics
0–6 km Shear8 kt
0–1 km Shear2 kt
Eff. Shear13 kt
0–1 km SRH-7
0–3 km SRH1
Eff. SRH1
Storm Motion149° @ 21 kt
0–1 km EHI-0.1
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index31.4
Thermo & Levels
PWAT1.77 in
0–3 km LR8.4 °C/km
700–500 LR5.6 °C/km
Total Totals45.8
LCL793 hPa
LFC990 hPa
EL153 hPa
Freezing Lvl15,981 ft