"Unknown Factor" needed

Good Day All

I am currently handling a temperature estimation project related to drop of temperature for different type of liquid in storage tanks. The scenario is like this - There are 14 Tanks filled with different type of liquid (max 4 types). I am also taking Air Temp in consideration. So I have following variables:
1. Liquid Quantity
2. Liquid Actual Temp
3. Air Temperature
4. Wind Force
5. Wet/Dry Factor (to account for rainy seasons)
6. Projected Temp after 24 hours

For the sixth variable, I have applied Thermodynamics formula to come up with projected temp using principle of heat loss through conduction, convection and radiation etc. The projected figures are close but not close enough to the actual temp.

Guess, there remains a "unknown factor" which will eventually close down the gap between Actual and Projected Temp, something which I need to calculate. Being student of Computer Science and software engineering, Statistics is not subject, hence request help from someone. The data attached in a MS Excel file.


TS Contributor
Are these liquid at ambient conditions, or must they be pressurized to become liquid? If the latter, you will have a combination of liquid and gas and will have to include the heat involved in the transition from liquid to gas.