Pool Timer Hours to Run based on Temperature

I am looking for a SmartApp that will take the High temp for the day and divide that by 10 to give the hours for the pump to run that day. Is there anyone out there that could create that if that is not already done?


You can create yourself using webCoRE and a simple expression. Head on over to the webCoRE forum to get started!

So there is a way to take today’s projected High for the day, but at 4 o’clock it runs that calculation and then sets the Run Time for the Pool Pump Timer for that day. So each day the timer run-time would be different based on the time it did the calculation at 4 in the morning?

All of what you say seems physically possible using WebCore, but I’m not sure I understand what you’re trying to do.

So at 4am, the projected high for the day is 10°C. You then divide that temperature by 10? i.e. 1? What do you then do with that number?

I would head on over to the webCoRE forum. You will be using this feature:


Simple forecast
Returns the high temperature for today and next 3 days. Add .celsius or .fahrenheit to the end for metric and imperial respectively.
[[celsius:32, fahrenheit:89], [celsius:33, fahrenheit:92], [celsius:34, fahrenheit:94], [celsius:34, fahrenheit:94]]

You will create a variable that will pull in the High temp for the day then a simple expression that contains a simple math equation.

Not hard but you will have to do some research on understanding what webCoRE is and how it works and the great guys over at the webCoRE forum will jump on the opportunity to show off their webCoRE skills! :rofl:

I know this is an old post, but I wanted to do the same thing and this came up in the search results. I already had webCoRE configured so after I learned a bit more, I created the following piston. By default, the piston will turn on the pool pump at 11:00pm (you can adjust this) and will turn off after X hours (where X is the forecasted high temperature divided by 10).


  • Pool pump connected to SmartThings via switch, relay, etc.
  • SmartThings Virtual Switch named “Pool Automation”
  • webCoRE set up and configured


  • Define the StartTime variable. This is when your pool pump will start running. By default it’s 11pm, but it can be changed to whatever time you’d like.
  • Define the MinDuration variable. This is the minimum time that you want your pool pump to run on a daily basis. I added this so if you want the pump to run at least 5 hours a day, it will still do that even in the colder parts of the year.