Rachio not detecting heavy rain

This has happened several times before, but when it did usually it was chiseling and the rain wasn’t forecasted and it had happened out of the blue so I didnt really care.

However, yesterday (and an event like this happened 1 week ago as well) we had “severe thunderstorm” warning all day and it poured rain non stop for 2.5 hours during which there was a period of 30 minutes of hurricane level rain (so bad that my roof leaked, just to give you an idea).

Yet, Rachio tried to water multiple zones for 2 hours. I had to manually cancel it. Here is what happened chronologically:

  • Severe thunderstorm warning issued 9am in the morning between hours of 6pm and 10pm
  • Rain starts at 4:30 pm
  • Very heavy rain and lightning hits around 6:00pm and lasts till 6:45 ish
  • Rain continues all night on and off till 9pm
  • Rachio tries watering on schedule at 7:30pm

What’s going on here? If I cannot trust Rachio, how can I use it? This is the second time when it tried to water during very heavy rain (not counting the multiple times it missed rain before - in my view this is unacceptable, it shouldn’t miss any rain at all).

I have flexible daily schedules and smart schedule and all other options turned before you ask. My username is DerStig as well so feel free to look at my profile. I am using a weather stations thats only a few miles away and I am 100% sure there was absolutely no way any meteorologist or any weather station in a 50 mile radius of where I live could have missed yesterday’s rain. I am also living 20 miles from Manhattan so not remotely in an area that is rural and wouldn’t have any decent weather station.

What weather station are you using? Can you post a pic of the moisture levels of one of your zones with “More Detail” clicked on? That map help figure out what is going on.

I m using KMMU. It shows 11% moisture which is clearly wrong. It rained so much that I dont think it needs water for another 2-3 days. I have a moisture meter and it shows 10/10 wet on a scale of 1-10. I usually water when scale shows 2-3.

Seeing the “more detail” part of the moisture levels would help. I took a look at what KMMU is reporting. One site was showing “-” for precipitation for the last week, another site appeared to have KMMU reporting rain on the 18th, but it was only .03 inches. You may want to check out the data on some of the PWS’s near you and see if they are reporting rainfall amounts closer to what you actually got.

Since you’ve had this problem before, my guess is that the issue is with KMMU and a different weather station would serve you better. This doesn’t appear to be a problem with Rachio, but with the data that it is being fed.

Here’s what KMMU is showing for the 18th:

I see we are on to something, KEWR is newark international airport and is 13 miles away but has more accurate reporting. Is the weather station being 13 miles away a problem? There is another one 11 miles away but that only reported 0.3 inches whereas newark reported 0.68 inches which is a big difference.

It depends. I personally use a PWS that is a couple of miles from my house, just because it’s rain totals are much closer to what I get at my house than the rain at any of the National Weather Stations around me.

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For daily flex schedules, Rachio checks weather once a day, around midnight UTC, which is 8 PM in Manhattan. Rachio would have been using forecasted weather from 8PM the previous evening for your 7:30 PM cycle, which probably was before the rain alert.

You can see in the moisture level details that Rachio is using forecast data for the current day.

My wish list for V3 is that flex daily gets a weather data refresh closer to watering time and recalculates moisture levels, instead of once a day.


Hey @Derstig-

You caught it, but just thought I would chime in. It looks like KMMU is not reporting precipitation, which is why Rachio did not skip. I see you skipped to KEWR, which is reporting precip, so you should be good to go! Like @Linn mentioned, if you want to look into something a little closer, you can always check out the PWS’s in your area!

McKynzee :rachio:

Whats a PWS? How do I use them? Thanks for helping out

Personal Weather Station - run by weather enthusiasts or homeowners vs a weather service installation.

When you are choosing where you get your weather intelligence info from, theres a slider switch. Hit that and you will be shown all the Personal Weather Stations near you.

I recently had the same problem. My weather station reports precip but apparently either it was a delay or not enough to satisfy Rachio.

I decided to add a Rainbird WR2 rain sensor as a backup, and so far so good. They say rain sensors are discouraged but unless you have a weather station within a mile of your home I dont see how it can be accurate.

The WR2 is nice because you can select the amount of rain you want it to trigger at. The temp trigger is an added plua for local freeze protection as well. YMMV

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