temperature triggered irrigation (i wish)

I wish I had a drip irrigation timer that was temperature activated. Why? Because when it hits 90 in the hoophouse, I could let loose with the foggers, little gizmos that lets out a fine mist that felt really good, kind of like running through the sprinklers. Of course the point would be to cool off the plants a bit and pump up the humidity. But really I should avoid it I suppose as it's totally against the water restriction. If I wanted to do this I could set up a separate irrigation timer for the fogging system -- but it would be time triggered, not temp triggered. So it would go off hot days or cool days. However conveniently enough, I am pretty much always at home during the afternoon.