Flex Schedule experience

I’ve been fine tuning my own system for a few weeks now and wanted to share some knowledge with everyone that may or may not help.

What I found that helped most is adjusting the crop coefficient - in particular, adjusting this value to reflect ONLY the active watering months of the year. I live in Nebraska, so the default value (I assume for my zip code) is accurate for the year, but isn’t realistic because my system is flushed and off for 6 months of the year at least. After I realized this and averaged in only the watering months coefficients, my flex schedules are keeping up pretty well.

In my front yard zones I’ve set the allowed depletion to 40%, which also results in slightly more frequent watering.

Finally, upgrading my personal weather station has been a big lifesaver. I went from an ambient ws-1090 to a davis vantage vue which is like night and day as far as reliability and accuracy go.

Now that things are dialed in, it’s making it very easy to watch for and catch stressed parts of the lawn that prompt me to test run a zone for bad heads.

I do wish that when a hardwired rain sensor is being used, the system would be a little more lenient on rain skips. For instance…and i’m just pulling these numbers out of the air - if there’s a 40% chance of rain, and the system would normally skip that watering due to this, that it would take into account the rain sensor and reduce the rain chance threshold a bit knowing that a hardwired sensor would catch active rain and stop watering.

That’s a pretty minor quibble though.

Having used a CyberRain and Hydrawise until upgrading to the Rachio this year I can say without a doubt that it’s light years ahead of those two competitors.



Wonderful insight and thank you for sharing that with the community. Nice suggestion on the rain sensor improvement. I will pass that along to the development team.


Thank you so much for your real-world experience.

Just a question, with forecasted rain, assuming no physical rain sensor, what are your thoughts on this practice in general? Err on over/under watering? If below certain % assume no forecasted rain?


I prefer to err on the side of over-watering, but i’m sure it’s different in different parts of the country.

For me, it would be easier to let the soil dry out than it would to over water and try to catch up.

Thinking about it from a business perspective - i’d rather have people complaining about not saving as much on their water bills than complaining about stressed lawns.

But that’s also why I like having the physical rain sensor - in my case a hunter mini click - wired in…I just don’t want to hear my wife say “the sprinklers were running the rain”.

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Thanks, trying to understand where a certain threshold would be for ignoring forecasted rain.

Anything less than a X% chance of rain we ignore…ignore all forecasted rain for the day?

Thoughts on what you would be comfortable with?


I’d say only make a change to that setup IF a hardwired sensor is configured.

When I used a Hydrawise system, that setting was configurable and it was a real pain. That’s one of the reasons I finally went with a hardwired sensor.

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In CO we regularly receive forecasts for 50% chance of rain which is pretty useless. This means that it is equally likely to rain (or not).

I think Rachio would need to pick a threshold (like 50 or 60%) and assume it will rain above this threshold and ignore the chance or rain below this threshold.

Of course if there is a rain skip and it doesn’t actually rain the program should run the next day.
If it rains a lot more than predicted and you have a rain sensor than that will help prevent unnecessary watering.

Kind of what we do today. If POP is above 50% we take full forecasted value, if less than 50% we take half of the forecasted value.

It might make sense to even take less, maybe 25% of forecasted value if POP is less than 50%?

These types of things are so subjective since POP is made up of many variables we aren’t privy to.



I really like the idea of going down to taking much less of the forecasts under 50% than you do right now. I’m guessing that would be a relatively simple change. Long term I’d really like to have an option by zone where we could choose to ignore the forecast if it’s under some amount (like 20-30%).

During the hot summer days I’d rather take a chance of watering (and if we do get it the rain sensor will kick on) than have the plants stressed. And I’m sure there are other people who might want the exact opposite of this and make sure they save the water.

Thanks for continuing to look at this.