The red one is for the free API key (see its name).
The green ones are for OneCall API (subscription). You need a location device (current weather). Then you can add further devices for details (daily, hourly…).
If your location device is not working (wrong API key), the detail (child) devices won’t work, too.
Just create a OneCall API key and add a subscription. Add a limit for 1000 calls/day and you have a free API access 
hi, installed OW a couple of days ago and all working great. 2 days ago though, rain prediction and amount stopped working. all other metrics work. if I look in homey at the sensor, all data is updated except for rain prediction and amount. it has data of a couple of days old.
anybody have the same issue? any ideas on what to do to solve it?
thanks!
Thanks Ronny for the great app. It was very helpful in creating a flow that is designed to control my SmartWIngs Zigbee Outdoor Shades based on current weather conditions. Here is my latest YouTube video featuring the advanced Homey flow. Thanks again!
This looks really cool 
I already had an openweathermap API key, so started playing with this.
We have heat tape on the bottom edges of the roof to help prevent snow buildup, each one controlled via a smart switch. The ideal flow would be to turn them on when it’s actually snowing, and turn them off when it has not been snowing for at least 4 hours
I see 2 cards that might be useful -
I think either of those would be good to start the flow, turning on the heat tapes. XX mm is total accumulation, right ? But what is the units for the 2nd precipitation card, just XX ?
I’m not sure how to do the 2nd part, turning off the heat tape after 4 hours of no snow. Something along the lines of noting when snow precipitation stops and setting a variable or timer. Then checking that until it goes over 4 hours, then turning off the heat tapes.
Any ideas ?
Has anyone played with the Snow precipitation cards ? I’m not sure of the right way to do this - as mentioned above, I want to turn on the heat tape when it has snowed more than, say, 20mm. This is what I have - note the two paths
They both look right, but I don’t know the actual conditions to trigger them. I think the “becomes greater than” one is a one-shot right ? It will only trigger once, when the total snow accumulation goes over 20mm.
How often would the lower path fire ? I’m guessing whenever openweather updates the total accumulation, and that is checked every 5 mins (actually I think I set it to 15mins). But is that “snow precip is more than 20mm” the total accumulation ? Over what time period ? Or just since the last update ?
The perticiparion for current weather is only an estimated value for this day. It can happen or not.
A more realistic value you could get using thw daily history device. Based on the API description is should show the amount of precipitation in the past.
But I don’t know how exact it will be.
You can try a daily history device with an offset =0. This should be the amount from today (until now).
But: OWM only delivers percipitation (possible only rain or rain+show). You can check the values and use max.temp. as condition to check only percipitation is its <0°C.
The data depends on the local weather provider used by OWM for the country. Quality can be different…
