Get your own OpenWeatherMap API key
Sign up is easy. First you'll have to register as a user for OpenWeatherMap. The second step is to obtain an API key. Both steps are covered here.
The API key that you'll need for KWeather is free of cost.
1: Go to the OpenWeatherMap registration page and enter your personal details
You're now about to receive an e-mail with a confirmation link. Simple activate the liink to validate your e-mail address.
OK, so much for part 1. Are you ready for the next part? It is equally difficult....
2: Go to the 'Get API key page'
The first default key is already created, and ready to use. Additional keys can be created with the "Create key" options at the bottom of this page.
Copy the API key and paste it into the administrator panel of your KWeather module.