ORIGINAL: SD2006
I missed the temperature comment in your original post, sorry. I'd agree pressure is relevant in all of this, but a pressure difference between two air masses of equal temperature won't tell you which one will be holding more moisture. Besides, the two locations being compared in this thread probably aren't going to have a substantial difference in elevation.
Well I don't want to go into the details but there are loads of factors affecting air pressure, not least that the nearer to the poles you are the lower the pressure due to the atmosphere being thinner. So longitude is important to along with numerous other factors. florida is SUBSTANTIALLY nearer the equator than Scotland which is much nearer the poles.
Couple that along with the picture below showing mean water vapour levels and look closely where Scotland and florida are and you may well have to retract that statement.
Just remember air pressure and weather systems are more complex than you could possibly imagine even within (relatively) small areas such as a US state.