I've got a Samsung Gear S3 Frontier and a custom Facer Watchface. I've tried multiple ways to get the correct weather data but it's nearly always wrong or very wrong.
Right now I have the #WCCT# that's usually within a degree or two, yet is always different from the temperature both on my phone and in the native weather app on the watch (Weather 2.0.31 is all it says).
The #WTH# and #WTL# tags show incorrect data and I'm not even sure rcoaster knows what he means when he says "so far for the day" considering the day is 10 hours old and it's surely been colder than 20, yet that's what it's showing as the #WTL#. I'll try the "forecasted" one, but I agree that it's most likely for tomorrow (Forecast Day 1 surely wouldn't be today...).
And I'll ask the same question: Where does Facer get its weather data? I'm happy to install something on my phone to get my watch weather to be correct, I just need to know where to look.
I also found out that the weather won't update unless I've got my "location" turned on in my phone. It's a battery drainer, so I'd turned it off and set the weather app settings to be manual, but apparently that's not allowed.
It's too bad Facer's got such a neat design interface, because so much of the other stuff just doesn't effing work.