Rachio 3 Weather Intelligence + and local inputs (rain sensor &/or PWS)


My Rachio setup is located just past a large lake that often “shields” the area from summer thunderstorms thus most nearby weather stations would accurately report a heavy rain but my location would only receive a brief drizzle. As such I am interested in clarification on Rachio 3 WI+ and how it interacts with local inputs be it a rain sensor attached to the controller and/or PWS located on the same property as the Rachio. Will WI+ take into account those local inputs to improve accuracy or is it more of an either-or approach?


Not sure about Gen 3, but I have a Davis Vantage Vue with a Meteobridge to send its data to pwsweather.com and WU, and the Gen 2 looks solely to my PWS for rainfall data. I would think the Gen 3 would only improve on this.

It has been raining down here a lot in SE FL since May 13, and the Gen 2 history screens have exactly the same data as my weather station.

The forecasted rainfall is generated, according to Rachio, from a combination of the data provided solely by my Gen 2 and 30 years of weather history.

This has worked very well.

Note that for today 5/27, the 2.5 inch is the forecast. For all the previous days, the amount recorded is the actual rainfall, which is used in the MAD calculations.

Note that the rainfall reported by my PWS of 1.27 for 5/26 is the exact rainfall used by Rachio for that date’s MAD calculation.

The next screen shows the weekly rainfall, which you can see tracks with the rainfall Rachio recorded in the first screenshot

These screenshots show the forecast going out for the next 14 days, but these are updated daily or more often. Once the current moisture balance reaches 0% of your allowed depletion (which you set up in your zones, and defaults to 50% of the soil moisture possible depending on soil type and root depth) the system will water that zone. Note this is 0% of your allowed depletion, not 0% absolute soil moisture


One more interesting thing:

We are having very heavy rain today, and once the actual rainfall exceeds the forecast, that rainfall replaces the forecasted rain in the soil moisture calculations. Note for 5/27 rainfall is now 2.68 inches, which is the amount we have had so far today, which has replaced the amount forecasted in the earlier screenshot I posted of 2.5 inches.

So it appears this is updated in near real time as the PWS reports the rainfall to pwsweather.com every minute!

We are indeed having a very wet May, and my Rachio has only watered once since May 10. My old system, with a backward looking rain sensor probably would have watered many times during this period.


@Eric33432 These are my favorite posts, I love these charts. :wink:



Thank you VERY VERY much for those great posts!! They were extremely helpful and certainly moves me much closer to adding a PWS to my setup.


I have had a Davis Vantage Vue weather station at my house since 2011, but it was never reporting to any of the weather web sites except for Davis’ own site. I had to get a device to poll the weather station as it cannot, on its own do that. Since I had the IP adapter for the weather station so it would report to the Davis site, it was fairly easy to install the Meteobridge device, which is a little TP link router running OpenWrt linux and the Meteobridge software, and all it needed was to be plugged into my network and everything works over Ethernet.

But I believe there are weather stations you can purchase that directly, without any other hardware, can report to Weather Underground, pwsweather.com, and others. If you purchase a weather station check to see if it can do that and it will be simpler and cheaper probably.

I think Rachio is pretty good, but with a PWS, it will be spot on accurate!