If you change "Rain" to "ain" it will work for both "Rain" and "Light rain". (It's case sensive).
I know that it's case sensitive, but I think Googles conditions are "Light Rain" and "Chance of Rain" so there is no need for a change.
Couldn't find a city with one of these conditions, but for example I know its "Partly Cloudy" and not "Partly cloudy".
But I noticed that gg.weather.getcustom command doesn't check the actual weather but uses the result from the last check.
So I added a getcurrent command in the first place.
Updated version in my first post!