Rain sensor and Flex Schedules


For Fixed schedules, a connected rain sensor serves to make the Iro skip any waterings that would have occurred while the rain sensor remains active (while it is still drying out), right?

For Flex schedules, I assume the rain sensor does essentially the same thing: prevents the Iro from watering while it is active.

However, I also assume that the rain that triggered the sensor is not accounted for in the Flex schedule. I guess the watering is delayed rather than skipped, in this case. Even though the waterings are delayed, the evapotranspiration data has not, so the Iro doesn’t know to recalculate. (I guess this assumes that the weather station data would have been off and your property received rain when none was observed at the selected weather station).

Is all that correct?

Is there any way to use a rain sensor as a poor man’s weather station and assume some amount of rain (configurable by the user, to match the setting on the sensor) in the Flex calculations?

If not, is there any benefit to a rain sensor when running only Flex schedules?


Precipitation is accounted for whatever weather station has been chosen.

Too hard from a software perspective, really needs to be automated.

Sure, if it is activated the schedule will be skipped. This is especially helpful if the weather station you are using doesn’t exactly reflect the precipitation you have received.

Hope this helps.



Thanks for the reply!

Right, but the signal from the rain sensor doesn’t cause any added water calculation, right? For a fixed schedule, it sorta does (I know there’s not actually any calculation needed in that case, but it can reduce the water to the lawn by skipping watering).

That’s what happens for a Fixed schedule: the watering is skipped. For a Flex schedule, the watering is delayed until after the sensor deactivates, right?

What I’m saying is, with a Fixed schedule, the rain sensor can make your lawn be watered less (less total water volume). For a Flex schedule, the rain sensor cannot reduce overall water usage, it would only push watering to a later date.

It might help to imagine that the weather station you’re looking at is broken and not reporting any rain. The rain sensor can help the Fixed schedule save water, but not the Flex schedule.

So I’m just trying to think if there is any reason to use a rain sensor if you use only Flex schedules.




Unless our observation the next day records the rain, which will offset evapotranspiration, which will essentially skip schedules until the zone is depeleted again.

Not as black and white, especially since rain sensor is real-time, and could augment our observation.

I would continue to use it, the more hyper local data, the better



im with ya, but transient yet conditional sources of data truly are the bane for any engineer.




on 2 different occasions now, my flex was skipped as it started raining between schedule finalization and the schedule executing, this in turned allowed the system to “catch up” with the weather data for the following day and unschedule my flexies. it was beautiful and harmonious. my wife and i provided a small golf clap session for rachio. so it still serves useful, albeit in a diminished capacity.





yea, she is a little butch, but a hell of a woman. sorry for poor quality, we just finished up work for the day.