At what point is the atmospheric pressure considered to be high or low?
Usually when you hear someone say &quot;high&quot; or &quot;low&quot; pressure, it is an abbreviated way of saying &quot;local maxima&quot; or &quot;local minima.&quot; And usually that pressure is the Mean Sea Level Pressure. By that definition, it is a singular point. But if you want to cover an area, you can probably reference a gridded dataset and plot the isobars. Then you can categorize the isobars as cyclonic (low pressure in Northern Hemisphere) or anticyclonic (high pressure in Northern Hemisphere). Then you can say if the location is enclosed in either, then it is in the respective area. You can make it however complex you want.
But if you want to create your own &quot;pressure climatology&quot; then you can probably do what you want to do.