This makes sense from a context and writer perspective.

Most conversation about climate change has been around global average temps raising in C. Further, switching that back and forth and doubling it for F would be seen as manipulative by people that don’t want to hear it.

On the contrary, the Times’s US audience (probably their main audience) thinks of body temp, which this is, in F.

To add further, the audience and writers that want to share cool, new dinosaur fact and the group that does an update on global warming are different people and operate and think differently around these specific things in these specific contexts.

Of course it would be easier to add the letter, but I can definitely see why it wasn’t included.