It’s just the wind!
We are camping on a bluff above Lake Meredith and as we went to bed we were still dealing with the high winds that have been with us our entire stay. Around 11PM, in a total of about 15 minutes, our 35 mph gusts out of the southwest became 25+mph gusts out of the north. It bounced us around quite a bit. It wasn’t long before windows slid closed and covers came up. The temperature dropped 20 degrees or more too. It wasn’t the most peaceful night’s sleep but we are definitely tired of 95F plus days and look forward to highs in the 70s and low 80s for a few.