Measurement location is at sea level so you compute the pressure.
Ph=Pr*(1-6.875585632/1000000*H)^5.25587611
Ph= pressure at H feet over reference r
Pr=1013.25 hPa or 760 mm Hg or 29.92 PSI at sea level, International Standard Atmosphere (ISA). True value changes.
Find it in weather maps, as it could go from as low as 860 hPa to as high as 1084 hPa [as recorded so far].
H in feet.
If H known in meters then make H=H/0.3048
If you are at 3000 ft [H] and sea level pressure is 1018 hPa [Pr], then your pressure is 912.37383 hPa [pH]
If still at 3000 ft [H] and sea level pressure goes to1030 hPa [Pr], then your pressure is 923.12873 [pH]
If still at 3000 ft [H] and sea level pressure drops to1000 hPa [Pr], then your pressure is 896.24149 hPa [pH]
No wind currents are accounted for, since those will change actual pressure on the basis of a new pressure amounting static and dynamic pressures. See Venturi effects.
Lots of gadgets out there [be careful] provide you barometric pressure at the touch of a button.