Evapotranspiration calculation and wind?

I was wondering if the evapotranspiration calculation takes into account wind conditions?

I found this online

A 5-mile-per-hour wind will increase still-air evapotranspiration by 20 percent

The local weather has been cool lately and I got an update email that my watering times have been adjusted downward. Cooler weather should mean less evapotranspiration so that makes sense, but its also been windy the past week or two as it often is here this time of year. My lawn looks dried out in parts, probably needing a bit more water. Does the formula look at local wind conditions when determining the evapotranspiration adjustment?


Thanks for reaching out to us Mike. That is a great point that you bring up.

Currently we are taking wind into account with our water budgeting (seasonal adjustment feature) as this plays a large part in ET values for your yard. How much have we reduced your durations recently? Just curious what those values are looking like now.

We don’t take wind into consideration with our weather intelligence feature though. So if you wanted to have this functionality I would suggest creating a recipe in IFTTT where you can select a wind threshold that will command a rain delay on the Iro. This can be beneficial to prevent watering when it is really windy and the sprinklers will be less effective.

We are going to be adding a wind threshold at some point in the future though. We are releasing the newest version of our software later this month and although it won’t be on the first version of the software we will be adding it a future release.

Let me know your thoughts Mike.


I’m in CA that has some strong water restrictions being enforced so I had to dial down the water from the initial recommendation. The last adjustment was from 10 down to 9 minutes.


Thanks for clarifying. If you have any additional questions please do not hesitate to reach out.

Thanks again for your support.