I have updated my calculators for how temperature and humidity effect runners. These calculators take into account your height and weight as well as running pace.
What will the temperature feel like when running? http://fellrnr.com/wiki/Perceived_Temperature_For_Runners
How fast can you run at different temperatures/humidities? http://fellrnr.com/wiki/Heat_limited_running_pace
What's the ideal temperature to run at? http://fellrnr.com/wiki/Optimum_Running_Temperature
The math behind the heat calculators http://fellrnr.com/wiki/Running_Heat_Model