Microsoft is shutting down the MSN weather service.
For Pimatic this has the effect that the pimatic-weather plugin won’t work anymore, since it’s based on the MSN service.
All users of pimatic-weather will have to switch over to pimatic-openweather.
This plugin is based on www.openweathermap.com.
Here you can learn howto set it up : http://www.pimatic.org/plugins/pimatic-openweather/
Also keep in mind to update your rules!