78665 Weather (Round Rock, TX)

Weather forecast for: Round Rock TX

Last Update: 8:38 am CDT Sep 6, 2026

Today: A slight chance of showers, then a chance of showers and thunderstorms after 10am. Partly sunny, with a high near 95. Heat index values as high as 107. Calm wind becoming south southeast around 5 mph in the afternoon. Chance of precipitation is 40%.

Tonight: Mostly clear, with a low around 76. South southeast wind around 5 mph becoming calm in the evening.

Labor Day: Mostly sunny, with a high near 98. Heat index values as high as 109. Calm wind becoming south southeast around 5 mph in the afternoon.

Monday Night: Mostly clear, with a low around 76. Southeast wind around 5 mph.

Tuesday: Sunny and hot, with a high near 99. Calm wind becoming south southeast around 5 mph in the afternoon.

Tuesday Night: Mostly clear, with a low around 76. Southeast wind around 5 mph.

Wednesday: Sunny, with a high near 98. Calm wind becoming south southeast around 5 mph in the afternoon.

Wednesday Night: Partly cloudy, with a low around 76. Southeast wind around 5 mph.

Thursday: Sunny and hot, with a high near 99. South southwest wind around 5 mph.

Thursday Night: Mostly clear, with a low around 76.

Friday: Mostly sunny and hot, with a high near 100.

Friday Night: Partly cloudy, with a low around 76.

Saturday: Mostly sunny and hot, with a high near 99.