issue_comments: 362796338

Thanks a lot @nbren12 ! Indeed _infer_interval_breaks is probably the right place to add this warning.

A few comments: - the tests are now failing, likely because of a type issue with time coordinates - coordinates don't have to be ascending for pcolormesh to work (see example below). Monotonically ascending and descending coordinates should work. - we need a test for this new behavior (asserting warnings) - we follow the pep8 conventions, and I think your lines are longer than the 79 character rule

python import numpy as np import xarray as xr x = np.arange(5)[::-1] y = np.arange(6)[::-1] x = xr.DataArray(x, dims=['x'], coords={'x': x}) y = xr.DataArray(y, dims=['y'], coords={'y': y}) z = x + y z.plot();