Rain Skip Threshold?

Hi all,

Relatively new to Rachio and loving my system – it’s already saving me a ton of water!

On that topic, I noticed that the default threshold for Rain Skip is .125, yet my zones are set to deliver roughly 1" of watering when activated.

Out of curiosity, what should be the relationship between rain threshold and watering amount? My naive assumption would be that the threshold should be close to the amount of watering required, but if that were the case, there wouldn’t be a need for a threshold in the first place.

Can someone shed some light on how to set the skip threshold relative to the watering time/volume being provided?


You can enable Rain skip on Fixed schedule, but not on Flexible schedule. Flexible schedule already takes into account actual and forecasted precipitation.
Based on Rain Skip FAQ, https://support.rachio.com/hc/en-us/articles/115010540788, Rachio will take into consideration the precipitation of last 24 hours, as well as the next 24 hours, and if it exceeds the threshold, it will skip it. If you put down about 1" of water, is this once per week? You might want to increase the threshold so that it doesn’t skip watering in that case.

There is also Saturation Skip for Fixed schedule. Here is the link for its FAQ: https://support.rachio.com/hc/en-us/articles/360000096188-Saturation-Skip-FAQ. This takes into consideration precipitation and irrigation amounts, and losses through evapotranspiration, to determine if an irrigation should be activated.

Are you considering the Flexible Daily schedule in the future?

Hi moisture,

Thanks for the response. I am indeed on a fixed schedule due to restrictions on when watering can occur in my county.

My question is around how to best set the threshold as the default is .125, and I’ll get messages on the day of the skip like, “skipped due to predicted 0.28 and observed 0.00 when compared to schedules threshold of 0.13”.

So if my sprinkers would normally deliver about 1" per zone, why is the default set to .125? Is there something I’m missing, or is it up to the user to figure out what amount is right given the various settings? (which seems odd, since I never tell the program how long to water as it figures it out itself…).

Just curious if there is a ‘best practices’ or formula for setting the threshold for my system.

Thanks again.

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@CrashNBurns, The rain threshold is a global threshold for the controller, and not customized for each schedule. I am not sure how many days you can water per week. You mention watering 1" per zone, so is this once a week? If it is once a week, you might not want to take a chance because Rain skip includes forecasted rain which might not actualize. This is the conundrum of water restrictions, they seem to promote more watering, especially if you have a smart controller that could reduce water in the long run but would require watering any day when needed. Check with your county to see if they provide variance for smart controllers, or send a letter to complain.

Hi moisture,

Ah, good info and definitely will seek more info about how to see if I could get a mitigation exception for my smart controller.

And apologies for the lack of details – not intentional on my part. It’s actually because I did so little to get it setup – it seemed to pick all the defaults and I just followed. So I’ll let you know what I know.

I am allowed to water two times per week (Wed/Sat), so I told the controller to use a fixed schedule. I have 6 zones (5 grass, 1 bubblers for bushes/shrubs). I set smart cycle – and weather intelligence (everything on; rain skip, freeze skip, wind skip, saturation skip, seasonal shift). I live in north-central FL, so quite warm/humid conditions, with direct sun on the lawn. Current durations (due to seasonal shift timings) are 21minutes for the grass zones, and 35 minutes for the bubbler zone, for 2h 25m total. The grass is Zoysia grass

Based on the old system I took out when I moved in, the zones were set for 15m for the grass zones.

Other than trying to draw out the zones in the app, I’ve done no other customization.

Looking at the default for the grass zone, it shows the nozzle inch per hour default at 1.5 in – which makes sense I guess, because a 21 minute run would lay down about .5 in each run, and at twice per week, that would be 1".

So given that the fixed ‘rain skip’ cycle limits its visibility to recent/upcoming potential rain, does a .125 rain skip default make sense, or should it be closer to the .5 threshold?

And on a slightly different topic, is a nozzle inch per hour default of 1.5 pretty standard, or should I tune this to match my specific sprinkler zones?

Thanks again for your help.

Since you are watering twice a week, and since Rain skip is looking at -24h and +24h (2 days), you can up it to 0.25in if Rachio is predicting actual rain correctly, or be conservative and use 0.5in. Saturation skip will also look at soil moisture and skip watering if all zones will have enough water till next watering cycle. Also monitor it the next time it rains to see how it is working out. I usually look at cocorahs.org for the daily precipitation as well as Personal Weather Stations in wunderground.com. I use Flex Daily and watering any day, so there is room for error because if it doesn’t need to wait 3 or 4 days to water in case it skips watering one day and predictions didn’t actualize.

For the irrigation precipitation rate, I would recommend doing a test, because the test will capture actual precipitation as well as efficiency. Rachio default for rotors is 1in/hour but mine was putting down 0.3in/hour. That’s a big difference.

Perfect - that makes sense – I’ll give that a try, and do the measurements as well.

Thanks again.