I tried to, but the first generation of Pebble watches have important hardware limitations, and it doesn't allow to run my current watch face engine.
Every 30 minutes, because I have found it is the sweet spot.
I don't recommend manual location because the automatic doesn't increase battery drain. Anyway if you want manual location, the expected codes for ZipCode,CountryCode are from this ISO specs.
Because they are the high/low current temperature deviation in your location area, not the high/low predictions in the forecast. If your current weather location is very accurate, it is normal that the three are alike.
* If the watch face is just installed, change to another watchface and then come back to desired watch face, and press again the settings button.
* You need Internet connection and Internet permission for the Pebble app, because settings pages are stored on Internet, so you don't disable it.
* (Only for iPhone) If you have entered an invalid manual location for weather, you should delete watchface, uninstall Pebble app from your mobile, and install both again.
* Could be a temporary problem on server (or you can not reach the server) where the setting pages are hosted. Click on the following link to check it.
* If you are connected by Wifi, switch to the 3G/4G connection and then try to open the settings page.
* (Only for Android) Pebble app requires "Draw over other apps" permission. Go to Android settings --> Aplications --> Application Manager or Gear icon --> Find Pebble and switch on Draw over Apps.
* Sometimes it is normal a deviation of 3-4C because OpenWeather service (free plan), in the worst case could have the weather data 2 hours old for some locations.