Answer: The air pressure
Explanation: condensation is basically the change of matter in the clouds from a solid phase to a liquid phase. To predict the weather, you might look at that with special equipment to see what the weather is. Air temperature, we know that we use that to predict the weather depending how cold or hot it is. Humidity is the wetness, so we use that too for the weather predictions. Air pressure is not really a factor in predicitng or describing it so i would choose that one. Hope this helps!