Forecast Vs Actual Crop Evap


I am noticing that the “forecast crop evap.” is way off the actual figure by a factor of 4. Is there something wrong with my setup? All my zones are doing the same.

Also, all may “actual crop evap” isthe same regardless if it rainy or a sunny day. It does not make sense to me.

Can you have a look at this for me?


@mckynzee can you have a look at this for me?

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@bizza - if you’ll post the settings in the application for the Side Lawn - both the standard (vegetation, soil, exposure, etc.) and the advanced (root depth, allowed depletion, efficiency, crop coefficient, etc.) one of the community members might chime in.

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Thanks @DLane,

Here are the settings.

I don’t think your settings really help show any problems with this issue. Your forecasted vs actual does vary greatly, but i would assume that’s based off the information provided from your weather station. Someone with Rachio would be better equipped to look into that info if that’s the case.

Hi @Bizza-

I apologize for the delay. My initial reaction is you Crop ET bumped up to a big change in weather- crop ET is just the ET provided by your weather station adjusted by your zone settings. Did you see this jump in all of your zones or just one?

McKynzee :rachio:

Hi @mckynzee,

It is the same for all my zones. 0.05cm crop evap.

Do you think it is the PWS that I am using. I am currently using the Wundergrond work around. My PWS is:

Hey @Bizza-

I remember you being in Australia… What have the temps been like there lately? I’m seeing that station report 50 deg F, which seems low to me, but if it’s reporting in celsuis that translates to 120 deg C, which seems insanely high.


@mckynzee - I think what @Bizza is questioning is the forecasted Crop Evapotransipiration is four times what was logged as actual on the prior days (see May 28 forecasted of .20 versus May 27 .05). @Bizza, out of curiosity what does the mositure level for the side lawn look like now? I’d like to see how the forecasted values for the 28th and 29th compared to what actually happened.

@DLane Agreed, I would be interested to see what they turned out to be. I got distracted by the weather station data… :nerd:

Hi @mckynzee & @DLane ,

Thanks for looking into this.

Below is the summary of the past weather, and the updated moisture levels.

The 28th & 29th Evap actuals ended up being 0.05 & 0.08. I was surprised at the 0.08 as that was an overcast and rainy day. The 0.05 days have been clear sunny days, so I would expect these Crop Evap to be higher.

The lawns and gardens had not been watered since the 6th May, so they where starting to look dry, hence I gave them a water yesterday. That is why I started to look at what was happening with the flex schedule.

I had a look at what a monthly flex schedule would do, and this suggested watering every 4 days. This would align with what the forecast crop evep. is estimating. I am thinking the daily flex schedule is not working as intended.

Here is the more of the history, if this helps.

Hi @mckynzee,

Have you been able to check if my Crop Evap. is reporting properly? My Actual Crop Evap is still reporting only 0.05cm for each day, even with different weather conditions. The forecast crop evap is 0.10 - 0.15cm.


I might be wrong, but could this be a metric units conversion problem? 1 in = 2.5 cm, which is similar to the ratio of forecast to actual ET (i.e. 0.13/0.05 = 2.6) 0.05cm is only 0.02 inches which seems low for ET.

Thanks @jkb.

@mckynzee, can you look into this please?

I found the below ET figures from the Australian BOM. If the Crop ET = ET x Crop coefficient, then my Crop ET is not recording properly.

Looking at these figures, the forecast Crop ET provided by Rachio looks to be a good forecast.

@mckynzee, can you please have a look at this???

Hey @Bizza-

I am going to have our development team look into the data your schedule is receiving from the weather station to determine if the issue is on that side or if we are receiving it incorrectly. Will report back.

McKynzee :rachio:

Hi @mckynzee

Here are the latest ET’s from Sydney Airport which is close by to check with the PWS data.

@mckynzee, any feedback from support yet?

Hi @mckynzee & @franz ,

Just read the below thread about PWS not sending UV data. I am using the WU to PWS setup. Could this be the reason the “Acutal ET” is not being reported correctly?