Hi,

Based on my limited research, it seems that temperature will have a bigger impact on refraction than barometric pressure - this is because of the magnitude and rapidity of change.

Both are important to input in APCC, but accurate temperature seems the most important.

https://en.m.wikipedia.org/wiki/Atmospheric_refraction

 

Refraction increases approximately 1% for every 0.9 kPa increase in pressure.  Similarly, refraction increases approximately 1% for every 3 °C decrease in temperature