Xarray data is often used in huge spatial datasets. We often need to fetch data in subregions. The following example shows you how to extract subset data from a large xarray.

import numpy as np
import xarray as xr

#set the sub domain box

min_lon = 100 
min_lat = 20
max_lon = 150
max_lat = 40

# read xarray data
fn='testfile.nc4'
ds=xr.open_dataset(fn,decode_times=False) #decode_times=True|False
cropped_ds = ds.sel(lat=slice(min_lat,max_lat), lon=slice(min_lon,max_lon))

#note: slice(min_lat,max_lat) or slice(max_lat,min_lat) depends on how your data is saved in the file. If data is saved from north to south, you should use slice(max_lat,min_lat)