Does anybody know of any good articles on the relationship between outside air temp and horsepower.

I ask because the weather is getting colder here in Texas and of course my car runs better, pulls harder and is just more fun.

Lets sa a car made 260whp with a heat soaked intercooler, on a 95 degree day with 50% humidity.

How big of an impact do weather conditions make on horsepower figures??
Makes me wish I had my own dyno