One of my former weather professors taught me a little trick when preparing a forecast.
The dew point temperature in the afternoon is often close to the temperature of the overnight low.
He didn’t go on to tell me why it works, but my experience is that it often does!
Of course, I use other methods when forecasting the overnight low, but I nearly always check the afternoon dew point and match it with my forecast.
Amazingly, the afternoon dew point nearly always tells me what to forecast for the overnight low!