I am able to determine that it starts @ 10 AM local time - like clockwork.
So something on a timer. Anything where the frequency isn't terribly well controlled and allowed to drift, which means probably lots possibilities. As others have mentioned, grow lights are possible or maybe a fish tank heater, a swimming pool pump, air conditioning, an air humidifier, HEPA filter unit, LED light power supplies, etc. Many possibilities.
It matters little but Las Vegas, NV is on Pacific Daylight Time right now, not Pacific Standard Time.