We have a similar feature developed as a plugin. It adds a new condition to the campaign.
You can then fetch a JSON API and evaluate the response. Based on the response, you can control the campaign flow. E.g. if it rains you can run this part of the campaign, or if there are new blogs available you send out a new email.
The plugin is currently only available with our Mautic hosting at aivie.ch. If there is enough demand for something like this, we can make it available as a plugin.