Countries/ States (NaturalEarth)

The outline of the countries are obtained from Natural Earth. They are automatically downloaded on-the-fly (but only once) with cartopy and opened with geopandas. The following countries and regions are defined in regionmask.

  • Countries 1:110m

  • Countries 1:50m

  • US States 1:50m

  • US States 1:10m


A mask obtained with a fine resolution dataset is not necessarily better. Always check your mask!

The following imports are necessary for the examples.

In [1]: import regionmask

In [2]: import matplotlib.pyplot as plt


In [3]: regionmask.defined_regions.natural_earth.countries_110.plot(add_label=False);

In [4]: plt.tight_layout()

US States

In [5]: states = regionmask.defined_regions.natural_earth.us_states_50

In [6]: states.plot(add_label=False);

In [7]: plt.tight_layout()

Also create a mask for a 1° grid over the US:

In [8]: import numpy as np

# create a grid
In [9]: lon = np.arange(200.5, 325)

In [10]: lat = np.arange(74.5, 14, -1)

In [11]: mask = states.mask(lon, lat)

In [12]: states.plot(add_label=False);

In [13]: mask.plot(add_colorbar=False)
Out[13]: <cartopy.mpl.geocollection.GeoQuadMesh at 0x7feb42ce2400>

In [14]: plt.tight_layout()