issue_comments: 285282066

Full disclosure, I am working with the same project as OP, but I am using a Linux machine (Ubuntu 16.04 LTS), having gotten the same package versions as OP, with Python 3.5.1 from Anaconda.

The problem is reproducible also on my machine, and I've done some more digging:

Tracing the different functions invoked from the first call to open_mfdataset() goes like this: open_mfdataset() -> auto_combine() -> _auto_concat() -> concat() -> _dataset_concat() -> _calc_concat_over() -> differs() -> equals()

Now, within the equals(), xarray tests for equality, and is """True if two DataArrays have the same dimensions, coordinates and values; otherwise False."""

With the example files OP tests for, all calls to equals() works fine until it reaches the variable "lat" (long name: latitude) (note that I am not sufficiently versed in these kinds of datasets to tell if "lat" is a variable or a coordinate, but at least it is treated as different than, say, "X", "Y" and "time".). Once the equals() function is invoked to tell if dataset[1:] is equal to dataset[0], it starts spitting out the CURL error.

This information does not illuminate the problem for me, but perhaps for any of you.