When does Rachio update weather forecast?

I’ve found the weather intelligence for my area to be way off, and am trying to update the Rachio weather to use PWS. However after choosing a PWS the weather forecast has not updated.

Can someone explain when Rachio updates the weather forecast? I read somewhere that it will update within 12 hr or 1 hr of a scheduled run, but obviously this is not sufficient if there was no run on a day that is now forecast to be very hot and Rachio should have run. Is it updating at least once a day? Can I force a weather update?

Forecast and PWS are separate. PWS measures actual weather events, and forecast information comes from whatever service Rachio subscribes to. Changing the PWS or WI+ isn’t going to change the forecasted weather.

Well that’s disappointing. Rachio weather is 8 degrees off today. There’s no way to make it more accurate?

There is a Weather Source option in the Controller Settings page of the app. I was assuming changing the source to a close weather station did something. Are you saying this doesn’t do anything to the forecast?

Forecasted temps or actual?

What schedule type are you running?

Forget about actual temperatures. How do I get Rachio to give me a forecast that is as good as my local weather underground forecast? Also, when does Rachio update its weather forecast? Nobody knows?

Weather forecasting is updated far in advance than you expect. I don’t know the exact time it is updated. I’ve had watering schedules skipped because it detected high rain chances 24-48hrs in advance. One thing I have found is that if you use the weather network for local weather events you could be relying on several stations located around your area and not necessarily near you. I found that purchasing my own tempest and using that provided more accurate results.


I too would like a definitive answers to: where does forecast come from? and also, when is forecast made? Also, what is purpose of selecting a PWS if it isn’t used to control my system?

Thanks for the input. I’m not sure I want to buy my own weather station, but out of curiosity how does Rachio read the forecast from your tempest?

It still does. Forecasting is for the future. PWS is for the now, what you are actually seeing.

What does Rachio do with PWS information?

It ends up being integrated with the Rachio app so when selecting your PWS you actual select your weather station instead of the weather network.

According to tmcgahey above, PWS is not used in forecasting though. Does that mean PWS does not effect scheduling? I would imagine the forecast is used for scheduling. Otherwise I’m totally lost.

I have a Davis Weather station linked to weather underground. And I have linked my Rachio to my station. Just the other day the scheduled amount of water was cut short because there was a rain event beyond what was forecasted after several days of 90 degree heat. So in the midst of the event, when the amount of rain exceeded 0.125 inches (in the end we received about 0.45 inches), I believe the Rachio controller just shut down the watering cycle scheduled for that run. In the end, I’m very happy with how the controller has made adjustments according to the weather using the flex schedule. But as I say, I have a personal weather station, so I don’t know how it might be different without that feature.

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He would be correct. PWS is for the now like he mentions. Since it is relying on the current weather it would not impact schedules unless there was a captured rain event on the same day or before, and meets your configured thresholds. e.g. .25” or more of rain before rain skip is activated. Forecasting only comes into play if it’s forecasted to rain, then it proactively skips a schedule in anticipation it does rain. Like I mentioned before it skipped a schedule of mine 48hrs in advance. I would also assume Rachio uses their own thresholds before skipping a schedule, e.g. 90% chance. On the flip side it also skipped a day and it didn’t even rain so I had to cancel the rain skip.

Back to your original question. Forecast is not based off PWS, forecast is based off your city which 9/10 times is the airport or something of the likes. PWS only comes into play for current events and actual temps near you. I would honestly ignore forecast and only worry about current events and actual temps per your nearest weather station. That would dictate impact on scheduled events more so than a forecast. From my experience forecast rarely does anything. It’s my tempest (or for your case closest PWS) feeding data inputs to determine scheduling.

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Thanks for the clarification. I was worried that the forecast I saw in the app wasn’t that accurate, but maybe it doesn’t matter as long as I select a close PWS.

right, and here, rain forecasts more than 12 hours off are highly useless. I’ve had many waterings skipped b/c of this but no rain ever come and the 90+ degree heat just kept sapping the moisture out of the ground.

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Again, to clarify, the forecasted weather is for the future. PWS data is for the now and the past. Per the documents, Rachio checks the weather twice prior to a run, and can adjust a skip accordingly. Now, what I don’t know is what the percentage threshold is for rain to cause a skip, but the amount thresholds are spelled out. Speaking of that, if you haven’t already, I’d highly recommend that you raise the default .25" rainfall threshold up. Realistically, no zone in your yard is going to be “full” with only .25" of rain, and having it that low might cause more false rain skips…

How does Rain Skip work?

Rain Skip checks the weather twice. Once twelve hours before and then again one hour before your watering schedule starts. Any time a schedule’s preselected rainfall threshold is met using observed and forecasted rainfall (rainfall in the last 24 and the next 24 hours forecast), the watering schedule is skipped. For example, if you have your rain threshold set to 0.5", and it rained 0.25" in the last 24 hours and is expected to water more than 0.25" in the next 24 hours, your schedule will be skipped.

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I changed the weather source to a station that was closer to our location . Since then we have had excellent forecasting . Just the other a scheduled rain skip was reversed hours before it was scheduled as the weather station said the storm moved away from our area

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I had my own weather station on WU before I got my Rachio system. I was delighted to find out that I could use it for forecasting. Rain is hyperlocal where I am and I’m thrilled that it gets picked up from my station instead of a conglomeration of 300 stations around me.