Triggering file sensor to read file

I would like to import data from a file that is updated hourly. It seems like the file sensor is the correct way to do this, but I do not see how to trigger it to run each hour. All the documentation examples and those on the web address how to set it up, but they look like they run only at startup.

How can I set the polling frequency?

My ultimate objective is to pull prior day precipitation totals from the National Weather Service and load them into a sensor value. I have written the python script to scrape the page, select the relevant value, and write it into a text file. Is there a better way to get local data into a sensor value?

Publish to an mqtt topic?

You mean something like trigger the automation every x minutes?

That is a good Idea tom. It would be simple and clean.

Still curious how the file sensor works/triggers though.