Normally a PWS reports rain with the same frequency it reports other data. The frequency is set by the owner - typically 5 to 10 minutes although you . choose longer or shorter intervals as you wish. I have mine set to 5 minute intervals and it reports three rain items to CWOP: rain in the last hour, rain in the last 24 hours, and rain since last midnight (the first two incorrectly at present!).
Oh yes I’m already loving the Rachio!