That depends on where you live. I used to live in a place where the lows are night were still very warm. Most of the night was too hot. Just before sunrise there was a moment when outside air was worth bringing in - but it was only long enough to cool the air in the house, not the mass of the house itself.

Now I live in a cooler climate. The highs can still get as high in the day, but it does cool of at night - nearly as soon as the sun goes down.